Icons Improve Older and Younger Adults' Comprehension of Medication Information
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Journal of Gerontology: PSYCHOLOGICAL SCIENCES Copyright 1998 by The Gerontological Society of America 1998, Vol. 53B, No. 4, P24O-P254 Icons Improve Older and Younger Adults' Comprehension of Medication Information Daniel G. Morrow,1 Catherine M. Hier,1 William E. Menard,1 and Von O. Leirer2 'University of New Hampshire, Durham. 2 Decision Systems, Los Altos, California. We examined whether timeline icons improved older and younger adults' comprehension of medication informa- tion. In Experiment 1, comprehension of instructions with the icon (icon/text format) and without the icon (text- only format) was assessed by questions about information that was (a) implicit in the text but depicted explicitly by the icon (total dose in a 24 hour period), (b) stated and depicted in the icon/text condition (medication dose and times), and (c) stated but not depicted by the icon (e.g., side effects). In a separate task, participants also recalled medication instructions (with or without the icon) after a study period. We found that questions about dose and time information were answered more quickly and accurately when the icon was present in the instructions. Notably, icon benefits were greater for information that was implicit rather than stated in the text. This finding suggests that icons can improve older and younger adults' comprehension by reducing the need to draw some inferences. The icon also reduced effective study time (study time per item recalled). In Experiment 2, icon benefits did not occur for a less integrated version of the timeline icon thai, like the text, required participants to integrate dose and time in- formation in order to identify the total daily dose. The integrated version of the icon again improved comprehen- sion, as in Experiment 1, as well as drawing inferences from memory. These findings show that integrated timeline icons improved comprehension primarily by aiding the integration of dose and time information. These findings are discussed in terms of a situation model approach to comprehension. W E investigated the influence of icons (pictorials) on the comprehension of expanded medication instruc- tions. Expanded instructions are more complete than stan- working memory (Glenberg & Langston, 1992; Larkin & Simon, 1987). Picture superiority effects in memory have been found for both older and younger adults (e.g., Park, dard medication container labels, providing information Puglisi, & Smith, 1986; Winograd, Smith, & Simon, 1982). about the purpose and possible side effects of medication On the other hand, icons have drawbacks. For example, as well as dose, time, and other information usually found they tend to be less familiar than text and do not depict se- on labels (Morrow, Leirer, & Sheikh, 1988). Such instruc- mantic or hierarchical information easily (see Wickens, tions are now provided with new prescriptions by many 1992, for a review). Thus, it is not surprising that studies pharmacies. However, they may be difficult to understand comparing icon and text formats in medication instructions and remember because they are more complex than labels have produced conflicting results. Some find that icons are (Food and Drug Administration [FDA], 1995). This is es- better understood than text (Day, 1988); others find that pecially the case for older adults, who tend to use more icons are less effective than text (Morrow, Leirer, & An- health services than younger adults do (World Health Orga- drassy, 1996) or that they are difficult to interpret (Wolff & nization, 1981). At the same time, older adults tend to ex- Wogalter, 1993). Morrell, Park, and Poon (1990) found that perience gradual declines in the cognitive resources neces- icons improved younger adults' recall for medication labels sary for understanding new information (Craik & Jennings, but decreased older adults' recall of the same information. 1992; Salthouse, 1991). Our earlier studies investigated There is greater consensus that instructions with both text (verbal) formats for expanded medication instructions text and icon formats are more effective than instructions (Morrow, Leirer, Andrassy, Tanke, & Stine-Morrow, 1996; with either format alone. Textbooks (see Levin, 1981, for a Morrow, Leirer, Andrassy, Hier, & Menard, 1997); the pre- review), instructions (Morrell & Park, 1993; Wickens, sent study examined whether instructions are also im- 1992), and product labels (e.g., Young & Wogalter, 1990) proved by including an icon that depicts medication dose are often better understood when accompanied by illustra- and time information. tions. Because some medication information is not depicted easily (e.g., purpose), medication instructions are likely to Icon and Text Formats in Medication Instructions contain icons that depict some but not all of the informa- Icons may be more effective than text formats for con- tion conveyed by the text. veying medication information. For example, icons are We investigated whether the timeline icon in Figure 1 more likely to be coded multiply (Paivio, 1971) or more improves comprehension when added to text instructions distinctively (Nelson, 1979) in long-term memory com- (note that the icon contains some verbal labels and thus is pared to the corresponding verbal information. Icons may not a strictly graphic format). This icon depicts medication also be more explicit than text, thus reducing demands on dose and time information, so that this information is both P240
ICONS AND MEDICATION INSTRUCTIONS P241 White Pills Identifying your medicine 1. Name of doctor: Your doctor is Dr. Farley. You can call Dr. Farley at (603) 436-2200. 2. Name of medicine: The name of your medicine is White Pills. 3. Purpose of medicine: Your White Pills are for relief of symptoms from seasonal allergies. How to take your medicine 4. Dose: Take two pills each time. 5. Time to take medicine: Take the White Pills four times each day. You should take your medicine at 8 a.m. in the morning, 12 noon, 4 p.m. in the afternoon, and 8 p.m. in the evening. 6. How long to take medicine: Take your White Pills for two weeks. 7. Warnings: Take with a full glass of water. If you miss a dose, take immediately upon remembering. Possible side effects 8. Mild side effects: Continue to take your medicine even if you experience an increase in appetite or feel weak. Consult your doctor only if these symptoms persist. 9. Dangerous side effects: Stop taking the White Pills and call Dr. Farley if you experience heart palpitations or perspire excessively. 10. In case of emergency, use your telephone and dial 911. Figure 1. Example of expanded instructions with integrated icon (Experiment 1). depicted (conveyed by the icon) and stated (conveyed by combining text and icon formats or the influence of the text) whereas other information (e.g., side effects) is only timeline on inferential processes. We investigated two pos- provided in the instructions. Note that the icon also depicts sible explanations for why icons may improve comprehen- the total daily dose (the number of pills taken in a 24-hour sion of medication information. period), whereas this information is implicit in the text and must be inferred by combining dose ("take two pills") and Situation models and instruction comprehension.—First, time ("take four times a day") information. Morrow, Leirer, icons may help the reader create a situation model (or men- and Andrassy (1996) found that dose and time information tal model) of the described task (e.g., Glenberg & Langston, was interpreted more accurately when conveyed by this 1992). Situation models represent what the text is about and timeline than when conveyed by two versions of a clock can be distinguished from a representation of the text itself icon. Moreover, the timeline was interpreted as accurately (van Dijk & Kintsch, 1983). Thus, this type of representa- as a text schedule, although the text was recalled better. tion is critical to linking instructions to the context of the However, this study did not examine possible benefits of task. Creating a situation model involves integrating infor-
P242 MORROW ETAL. mation from the instruction with knowledge about the task, both depicted and stated in the instructions compared to which often requires drawing inferences. Icons may facili- when it is only stated (text-only instructions). However, in- tate integration because, relative to text formats, they are formation in the instruction that is unrelated to the icon more compatible with how people represent information (e.g., side effects) should not be facilitated by the icon. Pre- such as quantity (e.g., medication dose) and time or sequence vious studies have found selective effects of pictures in (e.g., medication-taking times; Glenberg & Langston, 1992). illustrated text (Glenberg & Langston, 1992; Waddill & Icons may facilitate inferential processing in particular be- McDaniel, 1992). cause they are often more explicit than text, reducing the need for making inferences (e.g., Larkin & Simon, 1987). Repetition and instruction comprehension.—Repetition Thus, icons may reduce the demands of instruction compre- provides a second explanation for icon benefits in instruc- hension on working memory. tions. The timeline may improve comprehension simply by We examined whether the timeline improved inferences repeating information already stated in the instructions. about the total daily dose. Such inferences are involved in Repetition generally improves memory for verbal informa- loading a daily or weekly pill organizer, determining how tion (for a review, see Crowder, 1976). A related explana- many pills to take when away from home, and in other as- tion is dual coding theory, which predicts better memory pects of medication adherence. The timeline should facili- for combined format instructions because pictures and text tate such inferences because it conveys the total dose ex- are coded separately in memory, thereby benefitting re- plicitly whereas this information is only implicit in the text. trieval (Paivio, 1971). The repetition and situation model By directly or perceptually integrating dose and time infor- explanations predict benefits for information that is both mation, the icon may aid the mental integration required by depicted and stated but not for information that is only the inference (Wickens & Carswell, 1995). This prediction stated in the icon/text instructions (compared to the text- was tested in both experiments of this study. only condition). However, unlike the situation model ap- If the timeline improves comprehension by integrating proach, the repetition account does not predict greater ben- dose and time information, then these benefits should be re- efits of icons for implicit compared to stated information. duced if the icon is changed so that, like the text, it does not The repetition explanation also predicts that the integrated integrate dose and time information. Experiment 2 com- and nonintegrated versions of the timeline icon will im- pared the icon in Figure 1 (the integrated timeline) to a less prove comprehension to the same extent because the dose integrated version of the same icon (the nonintegrated time- and time information is repeated (presented pictorially as line, see Figure 2). The nonintegrated timeline indicated the well as verbally) in both cases. dose separately from the medication times, so that partici- pants would have to integrate dose and time information Aging and Icon Benefits mentally in order to identify the total daily dose. The situa- The timeline may reduce age differences in comprehen- tion model account predicts that the integrated icon should sion. In general, older adults should have more trouble un- be more effective than either the nonintegrated icon or the derstanding instructions because of age-related decrements text-only conditions, because the model is easier to con- in working memory capacity or speed of processing (Salt- struct when the icon reduces the amount of integration re- house, 1991), particularly when comprehension requires quired to identify dose and time information. them to draw inferences (e.g., Cohen, 1979). According to The situation model account predicts that icons will fa- the environmental support hypothesis (Craik & Jennings, cilitate comprehension of depicted information that is 1992), external supports that reduce comprehension de- stated in the text as well as depicted information that is im- mands on limited cognitive resources should reduce age plicit in the text because icons attract attention (e.g., Glen- differences in performance. The timeline may serve as an berg & Langston, 1992). Thus, dose and time information environmental support by simplifying the process of creat- may be understood more quickly and accurately when it is ing a situation model from medication instructions (e.g., by KEY dose . © per time 0 0 -Tablet C7 - 1/2 Tablet 12 2 4 6 8 10 12 2 4 6 8 10 12 I I I I A I Noon Midnight A I A l A I Midnight I A.M. P.M. Figure 2. Example of nonintegrated icon (Experiment 2).
ICONS AND MEDICATION INSTRUCTIONS P243 facilitating inferences). There is some evidence that pic- However, Morrell, Park, and Poon (1989, 1990) have found tures provide such support: Age differences in recognition that unlimited study time does not reduce age differences in memory are reduced for meaningful pictures (Park, Smith, recalling medication instructions, suggesting an age-related Morrell, Puglisi, & Dudley, 1990). Therefore, the timeline decline in the ability to monitor comprehension. We also may reduce age differences in understanding or remember- examined the influence of both verbal abilities (measured ing medication information. by a vocabulary test) and spatial abilities (such as visualiza- On the other hand, adding icons to instructions may also tion or mental rotation) on age differences in recall of med- penalize older adults if additional resources are required to ication information because comprehension of instructions identify referential links between the icon and text formats with both text and icon formats may draw upon both types (Mayer & Sims, 1994). Morrell et al. (1990) found that of abilities (Baddeley, 1986; Morrell & Park, 1993). More adding icons to medication labels reduced older adults' re- specifically, spatial abilities may be involved in interpreting call, perhaps because the older participants had greater dif- the timeline icon because medication information is spa- ficulty than younger participants with integrating the verbal tially coded (e.g., medication times are coded by position of and nonverbal information, or translating from nonverbal to marks on the timeline). verbal formats during encoding or retrieval of the instruc- tions. The nonintegrated timeline in Experiment 2 may pe- Method nalize older adults to a greater extent than it does younger adults if it increases integration demands compared to the Participants integrated icon. Thirty-six older adults (19 men and 17 women) and 36 To summarize, we investigated whether icons improved younger adults (13 men and 23 women) participated. Older older and younger adults' comprehension and recall of adults (mean age = 72.4, range 64-90 years) were recruited medication instructions. The situation model account pre- from local senior centers and community organizations. dicts greater icon benefits for depicted information that is The younger adults (mean age = 22.3, range 20-30 years) implicit rather than stated in the text and no facilitation of were college students. Both the older (O) and younger (Y) nondepicted information. Moreover, icon benefits are ex- groups rated themselves as moderately healthy (7-point pected to be less likely to occur for the nonintegrated icon scale with 1 = very poor health and 7 = excellent health; in Experiment 2, which requires participants to integrate in- O = 5.4, Y = 5.5), t(10) < 1.0. Older participants had com- formation in order to identify the daily dose. The repetition pleted more years of education (O = 16.7, Y = 14.8), f(70) = explanation also predicts selective benefits (facilitation only 3.5,/?
P244 MORROW ETAL. content and organization of the text was identical in both was asked about the total dose in a 24-hour period, which versions and was based on our previous research (Morrow, required participants to integrate dose and time information Leirer, Andrassy, Tanke, et al., 1996; Morrow et al., in in the text-only condition. Question order was randomly press). Figure 1 shows that 10 types of medication informa- determined with one exception: The inference question was tion were grouped into 3 categories: "Identifying your presented before the direct questions about dose and time, medicine" (name and purpose), "How to take your so that answering the direct questions would not activate medicine" (e.g., dose, time, warnings), and "Possible side the information needed for the inference. Participants were effects" (outcomes). told to answer the questions as quickly and accurately as In the icon/text condition, the instructions contained a possible, and their answers were taped for later analysis. timeline icon that depicted medication dose and time, as Participants first practiced the search task procedure, but shown in Figure 1. The timeline was placed just below the not the specific formats, by answering questions about a corresponding text. Pretesting showed that older adults pre- magazine's table of contents. ferred this arrangement to a version in which the icon oc- curred below all of the text so that it would not disrupt text Instruction recall.—In this task, participants studied two coherence. This embedded icon arrangement is consistent sets of three expanded instructions each for later recall. All with research showing that illustrations should be placed three instructions were from the same format condition (the next to relevant text (e.g., Mayer & Sims, 1994). order of format conditions was counterbalanced across par- We also manipulated the complexity of the medication ticipants). Participants were told to study the three instruc- schedule in the instructions. Although complexity can be tions so that they could remember information about taking defined in different ways (see Park & Jones, 1997), in our the medication in their own words. They were given a max- study it was defined as the total number of pills per day for imum of 10 minutes to study the instructions (42% of older a single medication (i.e., the total dose). Complexity was and 39% of younger participants used the maximum time examined because more complex schedules (either more for the icon/text condition; 39% of participants in both medications or more complex schedules per medication) groups used the maximum time for the text-only condition). are sometimes associated with reduced memory for medi- After studying the three instructions, participants com- cation information (e.g., Morrell et al., 1989) and more ad- pleted a 2-minute distractor task and then recalled the three herence errors (see Park & Jones, 1997, for a review). instructions (each instruction was cued with the medication Complexity was manipulated between participants: For half name). of the participants, the total dose in the icon/text condition Between the two study-recall trials, participants com- was two (take one pill twice a day) while the total dose in pleted the Vocabulary test (Ekstrom et al., 1976), and the the text-only condition was eight (take two pills four times Object Rotation test (Schaie, 1985). Finally, preferences a day). The combination of schedule complexity and in- were measured by asking participants which version of the struction type was counterbalanced across participants in instruction (with or without the icon) was easier to under- each age group. stand, which did the better job of explaining how to take the medication, and which they would prefer to receive from Procedure their pharmacists. The study lasted about 2 hours and consisted of an in- struction comprehension task, an instruction recall task, and Results several cognitive ability tasks. The experiment began with a 2-minute session that familiarized participants with the Inference Accuracy timeline. After the experimenter explained how to interpret To investigate icon effects on how participants drew in- the icon, participants were given a new timeline and were ferences, data from the question about the total daily dose asked to paraphrase the depicted time and dose informa- (which required an inference in the text-only condition) tion. Next, they were each given two blank timelines and were compared to questions about dose and time informa- asked to fill in dose and time information as provided by tion stated in the text. Thus, only depicted information was the experimenter. All participants were able to use the time- investigated in this analysis. Accuracy (percent of correctly line correctly. Next, participants performed the two medica- answered questions) was analyzed by an Age (older or tion instruction tasks. younger) X Format (icon/text or text-only) X Question type (total daily dose, which is implicit in the text condition, or Instruction comprehension.—Ease of understanding the stated dose and time information) analysis of variance instructions was measured by the search task (Morrow et (ANOVA), with the latter two factors repeated measures. al., in press). Participants performed this task for two ex- Table 1 shows that questions were answered more accu- panded instructions, one with and one without the timeline rately when the icon was present, F(l,70) = 4.3, p < .05, icon (the order of the format conditions was counterbal- MSe - .05. Accuracy was also higher for questions about anced across participants). For each instruction, participants directly stated rather than implicit information, F(l,70) = had 15 seconds to look over the information and then, with 7.7, p < .001, MSe = .08. Although the Format X Question the instructions still in front of them, they answered nine type interaction did not reach significance, F(l,70) = 3.2, p questions about information stated in the instruction (e.g., < .08, MSe = .04, planned comparisons (p < .05) showed "What is the medicine used for?" and "At what times do that the icon improved accuracy for inference but not for di- you take the medicine?"). In addition, an inference question rect questions. This suggests that icon benefits were greater
ICONS AND MEDICATION INSTRUCTIONS P245 Table 1. Mean Accuracy (% Correct) and Answer Time (sec) for Questions About Stated" and Implicit Dose/Time Information (Experiment 1) Icon/Text Format Text-Only Format Direct Inference Direct Inference Row Mean Answer Accuracy Older 100.0 (0.0) 91.7(28.0) 98.6 (8.3) 80.6(40.1) 92.7 Younger 100.0(0.0) 88.9(31.9) 98.6 (8.3) 80.6(40.1) 92.0 Mean 100.0 90.3 98.6 80.6 Answer Time Older 1.1 (0.8) 4.6 (4.2) 1.4(0.8) 8.3 (6.1) 3.9 Younger 1.0(0.4) 2.7 (2.8) 1.1 (0.6) 4.7 (3.6) 2.4 Mean 1.1 3.7 1.3 6.5 Note: Values are means with standard deviations given in parentheses. "Mean of questions about medication dose and time stated in instructions. for questions requiring participants to integrate dose and Table 2. Mean Accuracy (% Correct) for Questions About Stated" time information than for questions that simply required and Implicit Dose/Time Information by Format identifying this information (but icon benefits on directly and Schedule Complexity (Experiment 1) stated information may have been limited by ceiling ef- Low Complexity High Complexity fects). Age did not influence accuracy and did not interact with the instruction or question variables. Format Direct Inference Direct Inference We also examined whether making inferences was more Icon/Text 100.0 (0.0) 88.9(31.9) 100.0 (0.0) 91.2(28.0) difficult for participants faced with more complex medica- Text-only 98.6 (8.3) 91.7(28.0) 98.6 (8.3) 69.5 (46.7) tion schedules (total dose = eight vs two pills per day) in the Note: Values are means with standard deviations given in parentheses. icon/text and text-only conditions. Accuracy and answer "Mean of questions about medication dose and time stated in instructions. time were analyzed by an Age X Complexity X Format X Question type ANOVA, with the latter two variables re- peated measures. Only the accuracy results are presented in this article, because complexity did not influence answer time. Our most important finding is that more complex Accuracy and Answer Time for Directly Stated Information schedules increased inference errors for text-only but not for The accuracy of identifying information that was stated in icon/text instructions, Format X Inference X Complexity in- the instruction was analyzed by an Age X Format (icon/text teraction F(l,68) = 4.5, p < .05, MSe = .04; see Table 2). or text-only) X Information type (depicted [dose/time] or other information [e.g., side effects] in the icon/text instruc- Inference Answer Time tions) ANOVA, with the latter two factors repeated mea- Answer time was defined as the interval between the off- sures. These analyses excluded the inference question. An set of the question and the beginning of the answer, and effect of Information type was not interesting in itself be- was measured blind to condition. Times for incorrect an- cause the depicted and other information varied on several swers were excluded. Table 1 shows that questions were dimensions (e.g., sentence length, word frequency), but the answered more quickly when the icon was present in the in- Information type X Format interaction tested whether icon structions, F(l,53) = 11.9, p < .01, MSe = 11.2, and for benefits were selective. The timeline improved comprehen- questions about direct rather than implicit dose/time infor- sion accuracy for information stated in the text; questions mation, F(l,53) = 99.8, p < .001, MSe = 8.4 (see Appendix, about icon/text instructions were answered more accurately Note 1). Most important, the time required to answer the than questions about text-only instructions (99.5% vs 98.5% implicit questions was reduced when the icon was present items correct), F(l,70) = 4.7, p < .05, MSe - .002. The For- in the instruction, Format X Question type interaction mat X Information type interaction was not significant, F(l,53) = 9.8, p < .01, MSe = 9.8, again suggesting that probably because of ceiling effects on the accuracy measure icon benefits were greater for questions requiring partici- (Depicted: icon/text = 100%, text-only = 98%; Other infor- pants to integrate dose and time information. mation: icon/text = 99%, text-only = 98%), F(l,70) < 1.0, Older adults answered questions more slowly than MSe = .003. Age effects were not significant. younger participants did, F(l,53) = 12.3, p < .001, MSe = Answer time for information stated in the text was ana- 9.7, and this age difference was greater for implicit than for lyzed the same way as accuracy. Times greater than three direct questions, Age X Question interaction F(l,53) = standard deviations above the mean for each participant were 10.3, p < .01, MSe = 8.4. However, the Age X Question X replaced by the mean for that condition (1.9% of responses Format interaction was not significant, F(l,53) < 1.0, sug- for older participants and 2.3% of responses for younger par- gesting that the icon benefitted older as well as younger ticipants). Times for incorrect answers were excluded. adults' abilities to draw inferences. The icon reduced answer time for depicted information
P246 MORROWETAL. (icon/text format =1.2 sec, text-only format =1.6 sec) but structions compared to text-only instructions. Converging not for other information (2.3 sec for both conditions), For- evidence is provided by the finding that study time was cor- mat X Information type interaction F(l,70) = 4.7, p < .05, related with icon instruction recall for older (r = .40, p < MSe = .48. Selective icon benefits were similar for older .05) but not younger participants (r = .18, p >.10). Study and younger participants, Age X Format X Information time did not predict text-only recall for either age group (O: type interaction F(l,70) < 1.0. The main effects of Format, r=.26,Y:r=.19). F(l,70) = 2.3, p > .10, MSe = .79, and Age (O = 2.0 sec, Y = 1.7 sec), F(l,70) = 3.3, p < .08, MSe = 1.9, were not sig- Individual Differences in Instruction Recall nificant. Depicted information was identified more quickly We examined whether cognitive ability and age predicted than other information in both format conditions, F(l,70) = recall of icon/text and text-only instructions. In a hierarchi- 92.2, p < .001, MSe = .70. This probably reflects the fact cal regression analysis, cognitive ability (OR and Voc) that dose and time information was easier to understand scores were entered as a block before age, because age dif- than the other information in the instruction (e.g., warnings, ferences occurred for these variables (see Table 3). Cogni- side effects) even when it was not depicted (in the text-only tive ability scores accounted for a significant amount of condition) because these items contained fewer (and higher variability in icon/text instruction recall (R2 = .09), F(2,65) frequency) words. = 3.3, p < .05. Participants with higher OR scores recalled these instructions more accurately, t = 2.1, p < .05, suggest- Instruction Study Time and Recall ing that adults with greater spatial abilities processed the Instruction study time was analyzed by an Age X Format instructions with the icon more effectively. Age also pre- ANOVA. Older and younger participants did not differ in dicted recall (R2 = .07), F(l,66) = 4.6, p < .05, although age overall study time (O = 7.8 min, Y = 8.0 min), F(l,70) < accounted for less variance than when it was entered first in 1.0, MSe = 8.8. However, older but not younger participants the equation (R2 = .10). This suggests that the influence of studied the instructions for a longer time when the icon was age was due at least in part to age differences in cognitive present (O: icon/text = 8.3 min, text = 7.2 min; Y = 8.0 min ability. The analysis of recall for the text-only instructions in both conditions), Age X Format interaction F(l,70) = showed that no variable accounted for a significant amount 5.8,/? .10. Discussion Because study time differed for the instruction format Adding timeline icons to expanded instructions improved conditions, we analyzed recall as a function of study time. comprehension of medication information. These benefits We examined the time participants required to encode in- were greater for information about the total daily dose, formation effectively from the instructions by dividing total study time by the amount of dose and time information that was recalled. Stine and Hindman (1994) used a similar "ef- fective study time" measure to analyze age differences in Table 3. First-Order Correlations Among Participant Age reading time and recall. Consistent with the cognitive slow- (0 = Younger, 1 = Older), Vocabulary Test Scores (Voc), ing hypothesis (Salthouse, 1991), older participants in our Object Rotation Test Scores (OR), and Recall and Study Time for Icon/Text and Text-Only Instructions (Experiment 1) study needed more time than younger adults did to recall an equivalent amount of information (O = 2.3 min vs Y = 1.3 Icon Text min per item recalled), F(l,70) = 12.2, p < .001, MSe = Icon Study Text Study 26.2. Notably, less study time was needed to recall informa- Voc OR Recall Time Recall Time tion when the icon was present (icon/text = 1.5 vs text-only Age .72*** -.35** _,47*** .06 -.30** -.14 = 2.1 min per item), F(l,70) = 4.3, p < .05, MSe = 20.9, Voc -.13 -.18 27* -.14 .03 suggesting that study time was more effective when the OR .26* .10 .12 .18 icon was present. The Age X Format interaction was not Icon Recall .26* 42*** 29* Icon Study Time .24* 70*** significant, F(l,70) < 1.0. This finding suggests that by tak- Text Recall .26* ing more time to study instructions with icons, both older and younger participants were better able to recall these in- *p < .05; **p < .01; ***/? < .001.
ICONS AND MEDICATION INSTRUCTIONS P247 which was conveyed explicitly by the icons but only im- ences by directly integrating time and dose information, plied by the text instructions, than for information that was then the nonintegrated timeline in Experiment 2 should be stated as well as depicted. Moreover, increasing the com- less effective because, like the text-only instructions, this plexity of the medication schedule increased inference version of the icon requires mental integration to identify errors for text-only instructions but not for instructions with the total daily dose. Indeed, the nonintegrated timeline may icons. Participants also identified information more quickly be no better than the text-only condition. Older adults may and accurately from instructions with icons, and this benefit find the nonintegrated timeline especially problematic if it occurred primarily for depicted information in the icon/text increases overall comprehension demands on working instructions. The icons also improved effective study time, memory compared to the other conditions. For example, reducing the study time needed to recall dose and time in- they may have to integrate dose and time information men- formation. However, the influence of the icons was less clear tally in order to interpret the nonintegrated timeline, and cut for the memory than for the comprehension measures. then combine this information with other information pro- Although older adults in Experiment 1 answered ques- vided only by the text. tions more slowly and recalled the instructions less accu- Second, comparing the two timeline icons provides an rately, they benefitted as much as younger adults from the additional test of the possible explanations for icon bene- timeline icons. They did not, however, take advantage of fits. The repetition hypothesis predicts that the two time- study time in order to recall the instructions as accurately lines should improve comprehension to the same extent be- as younger participants did. They spent about the same cause they both repeat the dose and time information stated amount of time as younger participants studying the text- in the text. The situation model account, on the other hand, only instructions, yet recalled less information. These re- predicts that the integrated icon should be more effective sults, as well as similar findings by Morrell, Park, and Poon because it reduces the mental integration required to create (1989, 1990), suggest that older adults do not monitor their a mental representation of the medication-taking task. comprehension processes accurately enough to adjust study Third, the nonintegrated timeline addresses the possibil- time when given the opportunity. They may benefit from ity that the icon benefits in Experiment 1 were due to pre- more explicit guidelines about what information to study training on the icon, which might provide an advantage and how much time to devote to it (Park, 1992). Indeed, the over the text-only condition. If pretraining, rather than the finding that older participants in our study spent more time icon itself, improved comprehension, then the two icons studying instructions when the icon was present provides should improve comprehension to the same extent in Ex- some evidence that older adults can adjust study strategies periment 2, because participants were familiarized with in response to external support. both timelines before the study. The finding that the timeline especially improved the Finally, Experiment 2 expanded the individual difference ability to identify information that was implied rather than measures of cognitive ability. Experiment 1 found that OR stated in the text supports the situation model rather than scores predicted memory for icon/text instructions. This the repetition explanation of icon benefits in instructions. relationship may reflect differences in processing speed, However, the critical inference effects occurred primarily working memory capacity, or spatial ability because the OR for comprehension time rather than for comprehension ac- task was timed. We therefore included a sentence span task, curacy or for recall. This experiment also did not directly which measures the ability to simultaneously store and investigate which aspects of the timeline improved compre- manipulate verbal information in working memory (Stine hension. Experiment 2 addressed both issues. & Hindman, 1994). If differences in working memory ca- pacity as well as spatial ability are involved in processing EXPERIMENT 2 the icon/text instructions, then sentence span scores may be In this experiment, we focused to a greater extent on the as important as OR scores (or more so) for predicting re- process of making inferences by including more inference call. An earlier study found that older and younger adults' questions and by including them in both the memory and performances on a map learning task were better predicted comprehension tasks. Thus, the recall and comprehension by this sentence span task than by a measure of visual- measures should both provide clearer evidence for the ben- ization (Morrow, Stine-Morrow, Leirer, Andrassy, & Kahn, efit of a well-designed timeline icon in the processing of 1997). medication information. We also wanted to provide more direct evidence that the Method timeline icon facilitates the inference process by reducing the need for mental integration of dose and time informa- Participants tion. To do this, the timeline from Experiment 1 (the inte- Forty-five older adults (15 men and 30 women) and 36 grated timeline) was compared to a similar timeline that younger adults (16 men and 19 women) participated. Older conveyed the dose and time information in a less integrated participants (mean age = 71.2, range 59-92 years) were re- manner; that is, the dose information was indicated by a cruited from local senior centers and community organiza- box separate from the timeline (for the nonintegrated time- tions. The younger participants (mean age = 18.6, range line, see Figure 2). Comparing the two timelines allowed us 18-21 years) were college students. Older and younger par- to address several issues. First, the comparison helped pin- ticipants did not differ in self-reported health (O = 5.5, point which aspects of the icon improve comprehension. If Y = 5.6), ?(79) < 1.0. Older participants had completed the timeline in Experiment 1 improved participants' infer- more years of education (O = 16.1, Y = 12.4), t(79) = 9.1,
P248 MORROW ETAL. p < .001, and scored higher on the Vocabulary test (Voc; mation stated in the text. Inference questions were inter- O = 27.7, Y = 14.6), f(79) = 13.1, p < .001. They scored spersed with the direct questions. lower on the Object Rotation test (OR; O = 16.9, Y = 39.6), Instruction memory.—The procedure was the same as in Working memory capacity was also measured by a sen- Experiment 1, except that participants studied one instruc- tence span task. Participants in this task responded "true" or tion rather than three instructions at a time (to reduce possi- "false" to progressively larger sets of spoken or printed sen- ble interference effects among the instructions, which tences and then recalled the last word of each sentence in might minimize icon effects on inference processes). They the set. The span score is the number of sentences (2-8) in studied each instruction for 1 minute rather than for an un- the largest set for which participants could recall all last limited study period. After studying each instruction, par- words (see Stine & Hindman, 1994, for more detail about ticipants completed a 1-minute distractor task and then materials and scoring). Older participants scored lower on answered the same types of questions as those in the com- this task (O = 3.6, Y = 4.2), ?(79) = 3.5, p < .001 (listening prehension task, except that they had to rely on their memo- and reading span scores were correlated, r - .35, p < .01). ries in order to answer the questions. Between the three study-test trials, participants com- Medication Instructions pleted the Vocabulary test (Ekstrom et al., 1976), the Object Six instructions from Experiment 1 were used in Experi- Rotation test (Schaie, 1985), and the sentence span task ment 2 (three for the comprehension task and three for the (Stine & Hindman, 1994). Preferences for the instructions memory task). Each instruction occurred in three versions: were measured by asking participants to rank the three in- the instruction either contained the icon used in Experiment struction versions according to which was easier to under- 1 (integrated timeline/text condition, see Figure 1), the stand, which did the better job of explaining how to take the timeline that indicated dose and time information sepa- pills, and which they would prefer to receive from their rately (nonintegrated timeline/text condition, see Figure 2), pharmacists. or no icon (text-only condition). We also expanded the inference questions used in the Results comprehension and memory tasks. In addition to the ques- tion about the total daily dose from Experiment 1, three Inference Accuracy questions asked how many pills participants would need to We investigated the influence of instruction format on the take with them if they were going to be away from home process of making inferences by comparing mean accuracy between specific hours (e.g, 3:00 p.m. to 7:00 p.m.). We for the five questions about implicit dose and time informa- also asked at what time a dose should be taken if the first tion with accuracy for the two questions about stated dose dose of the day was missed. and time information. Accuracy (percent correct answers) Older and younger participants were randomly assigned was analyzed by an Age X Format (integrated icon/text, to three presentation groups. Each group saw each instruc- nonintegrated icon/text, text-only) X Question type (ques- tion in a different instruction format condition. Also, for tions about implicit or stated information) ANOVA, with each presentation group, each instruction occurred with a the latter two factors repeated measures. different level of schedule complexity: a total daily dose of Instruction format influenced question accuracy, F(2,158) two (one pill twice per day), six (two pills three times per = 10.9, p < .001, MSe = .01. Table 4 shows that, as in Ex- day), or eight (2 pills four times per day). A counterbalanc- periment 1, the integrated icon was more effective than the ing scheme ensured that all combinations of instruction for- text-only condition, f(80) = 4.3, p < .001. It was also more mat and schedule complexity occurred across the three pre- effective than the nonintegrated icon, f(80) = 3.2, p < .001. sentation groups. Order of presentation of the instructions The difference between the nonintegrated icon and the text- was varied across participants in each group. only conditions did not reach significance, f(80) = 1.8, p < .10. The Age X Format interaction approached signifi- Procedure cance, F(2,158) = 2.7, p < .10, but Table 4 shows that the The session lasted about 90 minutes and consisted of the integrated icon improved accuracy for both older and medication instruction comprehension and memory tasks as younger participants. well as several cognitive ability tasks. The study started with Icon benefits were greater for questions about implicit in- a 3-minute period that familiarized participants with the two formation than for questions about stated information, For- types of timelines. All participants used both timelines cor- mat X Question type interaction F(2,158) = 8.6, p < .001, rectly by the end of this introductory period. Next, partici- MSe = .02. The integrated icon improved inference accu- pants performed the two medication instruction tasks. racy compared to both the text-only condition, t(SO) = 4.3, p < .001, and the nonintegrated icon condition, f(80) = 3.0, Instruction comprehension.—Ease of understanding the p < .001. However, differences between instruction condi- instructions was again measured by the search task. Partici- tions were not significant for questions about stated infor- pants performed this task for three instructions: one with mation (all ps > .10), reflecting ceiling effects on this mea- the integrated timeline, one with the nonintegrated timeline, sure. Questions about stated information were answered and one without an icon. The procedure was the same as in more accurately than implicit questions, F(l,79) = 77.4, p < Experiment 1, except that participants answered five infer- .001, MSe = .02. Age did not influence accuracy and did not ence questions in addition to the nine questions about infor- interact with the inference variable.
ICONS AND MEDICATION INSTRUCTIONS P249 Table 4. Mean Accuracy (% Correct) for Questions About Table 5. Mean Accuracy (% Correct) for Implicit Dose/Time Implicit and Stated Dose/Time Information (Experiment 2) Questions by Format and Schedule Complexity (Experiment 2) Integrated Nonintegrated Row Low Medium High Icon Icon Text-Only Mean Format Complexity" Complexity" Complexity0 Inference Accuracy Older 92.0(12.4) 86.7(17.6) 84.9(21.4) 87.9 Integrated Icon 94.1 97.8 91.9 Younger 97.8 (6.4) 91.7(15.4) 81.1(24.4) 90.2 Nonintegrated Icon 94.8 82.2 89.6 Mean 94.9 89.2 83.0 Text-only 91.1 77.8 80.7 Direct Accuracy 'Two pills per day. Older b 100.0 (0.0) 99.3 (5.0) 100.0 (0.0) 99.8 Six pills per day. c Younger 100.0 (0.0) 100.0 (0.0) 98.6 (8.3) 99.5 Eight pills per day. Mean 100.0 99.7 99.3 Note: Values are means with standard deviations given in parentheses. Table 6. Mean Answer Time (in sec) for Implicit and Stated Dose/Time Questions (Experiment 2) Answer Times To examine if making inferences was more difficult for Question Type by Integrated Nonintegrated Row participants when faced with more complex medication Age Group Icon Icon Text-Only Mean schedules, the mean accuracy for questions about implicit Inference information was analyzed by an Age X Complexity (2,6,8 Older 2.8(1.5) 3.4(1.9) 4.0 (2.6) 5.1 pills per day) X Format (integrated icon, nonintegrated Younger 1.7(0.8) 2.2(1.8) 2.4(1.5) 3.2 icon, and text-only) ANOVA, with the latter two variables Mean 2.3 2.8 3.2 as repeated measures (see Table 5). A Complexity X For- Stated" mat interaction, F(2,75) = 4.2, p < .05, MSe = .03, was Older 1.1(0.6) 1.0(0.4) 1.1(0.6) 1.1 analyzed by examining the influence of complexity for each Younger 1.0(0.4) 1.1 (0.5) 1.2(0.5) 1.1 instruction type. As in Experiment 1, errors tended to in- Mean 1.1 1.1 1.2 crease with complexity for text-only instructions, F(2,80) = Note: Values are means with standard deviations given in parentheses. 2.7, p < .10, MSe = .01, with more errors for high rather 'Mean of questions about medication dose and time stated in instructions. than low complexity schedules (p < .05). A similar pattern occurred for the nonintegrated icon instructions, F(2,80) = 4.2, p < .05, with more errors for high than for low com- Accuracy and Answer Time for Stated Information plexity schedules (p < .05). On the other hand, comprehen- Accuracy of answering questions about information that sion of the integrated icon was not influenced by complex- was stated in the instructions was analyzed by an Age X ity, F(2,80) = 2.3, p > .10, MSe = .01. Errors did not differ Format X Information type (depicted or other information for high and low complexity schedules for this type of in- in the icon/text instructions) ANOVA, with the latter two struction (p> .10). factors repeated measures. These analyses excluded ques- tions about implicit information. Unlike Experiment 1, Inference Answer Time icons did not influence comprehension of stated informa- Answer times greater than three standard deviations tion (integrated icon 97%, nonintegrated icon = 97%, text- above the mean for each subject were replaced by the mean only = 98%), F(2,158) < 1.0, MSe = .003. The Format X for that condition (0.4% of responses for older participants Information type interaction was not significant, F(2,158) = and 0.6% of responses for younger participants). Incorrect 1.5, MSe = .003, again reflecting ceiling effects for the answers were excluded from the answer time analysis. The measure. An effect of Information type showed that ques- results for the answer time measure were similar to the ac- tions about depicted information were answered more accu- curacy measure. Answer time was influenced by instruction rately than questions about other information in the instruc- format, F(2,156) = 6.7, p < .01, MSe = 1.5 (see Table 6). tions (depicted = 99.5%, other = 95.3%), F(l,78) = 21.9, Answer time was faster for integrated icon instructions than MSe = .01. for text-only instructions, ?(80) = 3.7, p < .01. There was Answer time was analyzed in the same way as accuracy. also a nonsignificant trend for answer time to be faster for Times greater than three standard deviations above the the integrated icon instructions than for nonintegrated icon mean for each subject were replaced by the mean for that instructions, f(80) = 1.9,/? < .07. condition (0.2% of responses for both older and younger The Instruction X Question type interaction was signifi- participants). Times for incorrect answers were excluded. cant, F(2,156) = 5.5, p < .01, showing that the integrated Instruction format did not influence answer time for stated icon primarily reduced answer time for implicit rather than information (integrated icon = 1.7 sec, nonintegrated icon = stated information. Finally, answer time was slower for in- 1.8 sec, text-only = 1.9 sec), F(2,158) < 1.0, MSe = .77. ference questions than for direct questions, F(l,78) = 177.0, The Format X Information type interaction was not signifi- p < .001, MSe = 1.9, and this slowdown was greater for cant, F(2,158) = 1.2, MSe = .60. Questions about depicted older participants, Age X Question type, F(2,156) = 27.6, information were answered more quickly than questions /?< .001. about other information (depicted = 1.1 sec vs other = 2.5
P250 MORROW ETAL. sec), F(l,78) = 333.2, MSe = .79. This depiction effect was older participants. It was less effective than the integrated greater for older adults (O: depicted = 1.1 vs other = 2.7 icon, f(44) = 2.7, p < .05. There was also a nonsignificant sec; Y: depicted = 1.1 vs other = 2.4 sec), Age X Informa- difference in favor of text-only over the nonintegrated icon tion type interaction F(l,78) = 5.2,p < .05. instructions, ?(44) = 1.6, p > .10. Questions about stated information were answered more Memory for Implicit Information accurately than questions about implicit information, F(l,79) Memory for the instructions was measured by the per- = 14.6, p < .001, MSe = .02. Unlike the comprehension cent of correct answers to questions after each instruction measures, the Format X Question type interaction was not was studied. Mean accuracy for implicit questions and for significant for the memory measure, F(2,158) < 1.0, sug- questions about stated dose and time information was ana- gesting that the integrated icon had similar effects on im- lyzed by an Age X Format X Question type ANOVA, with plicit and stated information. Finally, older participants the latter two factors as repeated measures. generally remembered less than younger adults did, F(l,79) Instruction format influenced memory question accuracy, = 4.5, p < .05, MSe = .08, although both age groups remem- F(2,158) = 4.6, p < .05, MSe = .04. Table 7 shows that the bered the instructions very well. integrated icon improved memory for dose and time infor- mation compared to the text-only condition, t(SO) = 2.5, p < Memory for Stated Information .05, and to the nonintegrated icon condition, ?(80) = 3.1, p Accuracy of answering memory questions about stated < .001. The text-only and nonintegrated icon conditions did information was analyzed by an Age X Format X Informa- not differ, f(80)< 1.0. tion type ANOVA, with the latter two factors as repeated The influence of icons on instruction memory also de- measures. Instruction format influenced memory for stated pended on participant age, Age X Format interaction information (integrated icon = 82%, nonintegrated icon = F(2,158) = 3.3, p < .05. For younger participants, the inte- 78%, text-only = 78%), F(2,158) = 5.2, p < .01, MSe = .02. grated icon improved memory compared to the text-only The integrated icon improved memory relative to the text- condition, t(35) = 2.4, p < .05. This difference was not sig- only condition, f(80) = 2.7, p < .05. As in Experiment 1, the nificant for older participants, r(44) < 1.0 (although the Format X Information type interaction was not significant means were in the expected direction; see Table 7). The for instruction memory, F(2,158) < 1.0, MSe = .02, suggest- nonintegrated icon appeared to pose particular problems for ing that the icon helped participants remember both de- picted and other information in the instruction. Memory was better for depicted than for other information (depicted = 93% vs other = 66%), F(l,79) = 316.1, p < .001, MSe = Table 7. Mean Accuracy (% Correct) for Memory Questions .03, and this depiction effect was greater for older adults About Implicit and Stated Dose/Time Information (Experiment 2) (O: depicted = 91% vs other = 58%; Y: depicted = 95% vs other = 73%), F(l,79) = 11.4, p < .01. Overall memory was Accuracy lower for older than for younger adults (O = 75% vs Y = Information Type Integrated Nonintegrated Row 84%), F(l,79) = 15.2,p < .001, MSe = .07. by Age Group Icon Icon Text-Only Mean Implicit Individual Differences Older 88.0(18.8) 80.4 (22.4) 86.2 (20.8) 84.9 As in Experiment 1, we examined whether cognitive Younger 97.2 (08.5) 91.7(16.8) 85.0 (25.5) 88.1 ability and age predicted memory for dose and time infor- Mean 92.6 86.1 85.6 mation that was presented by instructions with and without Stated icons. Cognitive ability measures included the sentence Older 93.7 (15.2) 87.0 (20.4) 90.7 (19.3) 90.5 span, object rotation, and vocabulary tasks. The cognitive Younger 97.7(08.1) 96.3 (13.3) 90.7(21.2) 94.9 ability scores were entered as a block before age in a hier- Mean 95.5 91.7 90.7 archical regression analysis because age differences oc- Note: Values are means with standard deviations given in parentheses. curred for these variables (see Table 8). Table 8. First-Order Correlations Among Participant Age (0 = Younger, 1 = Older), Vocabulary Test Scores (Voc), Sentence Span Scores (Span), Object Rotation Test Scores (OR), and Recall for Inferred Information From Integrated Icon, Nonintegrated Icon, and Text-Only Instructions (Experiment 2) Integrated Icon Nonintegrated Icon Text Voc Span OR Recall Recall Recall Age .83*** _ 36*** -.51*** -.29** -.27* -.03 Voc -.23* _46*** -.21 -.14 .12 Span .18 27* 40*** .21 OR .34** .43*** .06 Integrated Icon Recall .29** .28* Nonintegrated Icon Recall .12 *p< .05; **/>
ICONS AND MEDICATION INSTRUCTIONS P251 The cognitive ability scores accounted for a significant with both icons. Nonetheless, it is still possible that this amount of variability in memory for the integrated icon in- familiarization contributed to the icon advantage because a structions (R2 =.16), F(3,77) = 5.0, p < .01. Participants no-training condition was not included in the study. with higher OR scores, t = 2.5, p < .05, and higher span Fourth, the findings from the sentence span task expand scores, t = 2.0, p < .05, recalled these instructions more ac- our earlier findings about the relationships between cogni- curately. Age did not predict memory when cognitive abil- tive ability and instruction memory. As in Experiment 1, ity was controlled (R2 = .003), F(l,79) < 1.0. A similar pat- the fact that OR scores predicted memory for instructions tern occurred for memory for the nonintegrated icon with icons but not for text-only instructions provides some instructions. Cognitive ability scores accounted for a signif- support for the prediction that participants with higher spa- icant amount of the variance (R2 = .31), F(3,77) = 11.3, p < tial abilities are better able to take advantage of icons (also .001, and participants with higher OR scores, t = 4.0, p < see Mayer & Sims, 1994; Morrell & Park, 1993). In addi- .001, and higher span scores, t = 3.6, p < .001, recalled tion, the finding that both sentence span and OR scores pre- these instructions more accurately. Age did not predict re- dicted memory for icon instructions suggests that these in- call with cognitive ability controlled (R2 = .002). Cognitive structions also required verbal or general working memory ability also predicted memory for the text-only instructions capacity. This is not surprising considering that much of the (R2 = .09), F(3,77) = 2.4, p < .10. However, only partici- information in the icon/text instructions was conveyed by pants with higher span scores, t = 2.l,p< .05, remembered text alone. Both experiments also showed that age differ- these instructions more accurately. Age did not predict re- ences in instruction memory were due in large part to age call when cognitive ability was controlled (R2 = .0003). differences in cognitive abilities. Finally, some findings in Experiment 2 were unexpected. Preferences The integrated icon did not facilitate comprehension of stated Most participants preferred the instruction with the inte- information as it did in Experiment 1, although it did facili- grated icon over the other two types of instructions. They tate memory for this information. Also, the integrated icon thought this instruction was easiest to understand (integrated did not improve older adults' memory for dose and time in- icon = 82% vs nonintegrated icon = 12% and text-only = formation, although it improved their comprehension of this 6%) and that it did the best job of explaining how to take the information. This issue is addressed in the general discussion. pills (integrated icon = 79% vs nonintegrated icon = 12% and text-only = 9%). They would prefer to receive this kind GENERAL DISCUSSION of instruction from their pharmacists (integrated icon = 78% vs nonintegrated icon = 14% and text-only = 8%). Benefits of Icons in Instructions Adding a timeline icon to expanded medication instruc- Discussion tions improved older and younger adults' comprehension. Experiment 2 extends the findings of the first experiment Several findings suggest that the timeline improved com- in several ways. First, it provides more evidence that the in- prehension by directly integrating dose and time informa- tegrated icon improves comprehension and memory accu- tion. First, icon benefits in both experiments occurred pri- racy as well as comprehension time. It also replicated the marily for total daily dose information, which was implied finding that the integrated icon primarily improved compre- by the text but conveyed directly by the timeline. Second, hension of implied information rather than dose and time icon benefits did not occur for the nonintegrated version of information stated in the text. Inference errors in both ex- the timeline in Experiment 2. Similar to the text-only in- periments also tended to increase with schedule complexity structions, this icon required readers to integrate dose and for the text-only instruction but not for the integrated icon time information in order to identify the daily dose. Third, condition. This supports the idea that the icon improved inference errors tended to increase with medication sched- comprehension by reducing the mental integration required ule complexity (number of pills per day) for the text-only to identify the total daily dose. and nonintegrated icon instructions, but not for the inte- Second, Experiment 2 helps identify the aspects of the grated icon instructions. timeline icon that facilitate comprehension and memory. The integrated icon also improved memory for medica- The finding that the integrated icon was more effective than tion instructions. It improved effective study time in Exper- the nonintegrated icon, which was usually no more effec- iment 1, reducing the study time participants needed to re- tive than text alone, suggests that the timeline improved call dose and time information. In Experiment 2, the same comprehension by directly or perceptually integrating dose icon improved participants' memory for the dose and time and time information. It is also interesting to note that the information that was implied by the text, even when their integrated icon was more effective than the nonintegrated study time was limited. version even though it contained more icon elements and The integrated icon improved comprehension and mem- thus could have been perceived as more cluttered, particu- ory for stated and implicit information in Experiment 1. larly by older participants. Participants identified stated information more quickly and Third, Experiment 2 suggests that the icon benefits were accurately from instructions with the integrated icon, and not due solely to prior exposure to the icons, because the these benefits primarily occurred for depicted information integrated timeline icon was more effective than the non- rather than other information in the instructions. The time- integrated timeline icon even though participants were line icon did not improve comprehension of stated informa- allowed the same amount of prestudy familiarization time tion in Experiment 2, presumably because of ceiling effects
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