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The Journal of General Psychology Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/vgen20
The Effect of Increased Incentive on Free Recall by Learning-Disabled and Nondisabled Children a
Richard H. Bauer & Verna Peller-Porth
a
a
Department of Psychology , Middle Tennessee State University , USA Published online: 06 Jul 2010.
To cite this article: Richard H. Bauer & Verna Peller-Porth (1990) The Effect of Increased Incentive on Free Recall by Learning-Disabled and Nondisabled Children, The Journal of General Psychology, 117:4, 447-461, DOI: 10.1080/00221309.1990.9921150 To link to this article: http://dx.doi.org/10.1080/00221309.1990.9921150
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or
indirectly in connection with, in relation to or arising out of the use of the Content.
Downloaded by [University of Iowa Libraries] at 08:31 19 April 2015
This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/terms-and-conditions
The Journal of General Psychology. J17(4),447-462
Downloaded by [University of Iowa Libraries] at 08:31 19 April 2015
The Effect of Increased Incentive on Free Recall by Learning-Disabled and Nondisabled Children RICHARD H. BAUER VERNA PELLER-PORTH Department of Psychology Middle Tennessee State University
ABSTRACT. Immediate free recall by learning-disabled and nondisabled children was compared under two incentive conditions. Recall of the first few words of each list by disabled children and younger nondisabled children was lower than that by older nondisabled children, and receiving a monetary reward increased early list item recall by older disabled and nondisabled learners. These findings suggest that elaborative encoding processes, such as rehearsal, are impaired in younger disabled and nondisabled children and that receiving a reward increased elaborative encoding by older children. Similar recall of the last few list items by all groups suggests that attention and immediate memory are comparable in disabled and nondisabled children of different ages. Receiving a reward increased recall of the last few list items by younger disabled and nondisabled children, suggesting that a reward increased attention, immediate memory, or both, in these groups. Because receiving a reward increased recall equally in all groups, lower motivation did not appear to be responsible for the lower recall by younger nondisabled children and learning-disabled children.
CHILDREN WITH LEARNING DISABILITIES perform at a lower level than do nondisabled children across a broad spectrum of behaviors (e.g., Cruickshank & Hallahan, 1975; Parrill-Burnstein, 1981; Swanson, 1987). Because many behavioral deficits are found in children with learning disabilities, a common factor may be responsible. Intelligence is, by definition, not lowered in disabled students, and for this reason, differences in intelligence can be excluded. Adequate motivation is necessary for high performance, and if there is a single underlying basis for learning disabilities, motivation may be the important factor. However, very little research has been devoted to examining the role of motivation in performance of the learning disabled. 447
Downloaded by [University of Iowa Libraries] at 08:31 19 April 2015
448
The Journal of General Psychology
Studies on the influence of explicit incentives on children with and without learning disabilities have reported conflicting results. Without explicit incentives, discrimination learning is slower in disabled than in nondisabled learners, but with explicit incentives acquisition rates by both groups are similar (Blair, 1972; Shores, 1969). Thus, without explicit reward, children with learning disabilities may be less motivated. However, receiving a monetary reward increased paired-associate learning and serial recall of drawings by students with and without learning disabilities to about the same degree (Goyen & Lyle, 1971; Haines & Torgesen, 1979), suggesting that incentives increased motivation of both groups. Torgesen and Houck (1980) found that, without monetary reward, digit recall by nondisabled children and learning-disabled children who had adequate digit recall decreased across trials and that monetary reward attenuated the decrease across trials. These results suggest that without additional incentives, motivation decreased across trials and that receiving monetary reward maintained a higher level of motivation. When no incentives were given to children with learning disabilities that had low digit recall, there was no significant decrease across trials, and reward had no significant effect on recall. Information processing deficits are thought to be an important component of learning disabilities (for a review, see Bauer, 1987), and lower-thannormal motivation may play an important role in impairing information processing. Therefore, results obtained by comparing information processing in children with and without learning disabilities when no additional incentives are provided and when explicit incentives are provided would have important implications for understanding learning disabilities. The major purpose of the present study was to compare information processing by children with and without learning disabilities under different incentive conditions. Because the information processing that occurs in immediate free recall is well defined (e.g., Atkinson & Shiffrin, 1971; Bauer, 1979), the immediate-free-recall task was used to investigate the influence of incentives. In immediate free recall, the first few items of each list are given more elaborative encoding, such as cumulative rehearsal and subjective reorganization, than are later items of each list. The more permanent storage produced by elaborative encoding is primarily responsible for the high recall of early list items (the primacy effect). Subjects recall the less permanently stored last few list items before recalling more permanently stored early list items because
The research was funded by the Middle Tennessee State University Program. We thank Rupert Klaus, Jerry Nash, and the teaching and administrative staff of the Murfreesboro and Hickman County school systems for their assistance in conducting this research. Requests for reprints should be sent to Richard H. Bauer, Department of Psychology, MiddLe Tennessee State University, Murfreesboro, TN 37132.
Downloaded by [University of Iowa Libraries] at 08:31 19 April 2015
Bauer & Peller-Porth
449
they are apparently aware that early recall of less permanently stored information increases recall of the last few items without interfering with recall of more permanently stored information. Recall of the last few items before recall of earlier items, attention, and immediate memory are primarily responsible for the high recall of the last few list items (the recency effect). The information processing that occurs in immediate free recall provides an opportunity to examine the influence of explicit reward on three major processes. Increased recall of the first few list items would suggest that incentives increase elaborative encoding. Higher recall of the last few list items on rewarded trials would suggest an increase in (a) attention and immediate memory, (b) the number of the last few items recalled before early item recall, or (c) both. To determine whether recall of the last few items was altered by monetary incentives, recall order was examined under no-incentive and incentive conditions. Thus, comparing performance of disabled and nondisabled groups in immediate free recall under no incentive and incentive conditions not only provides information concerning whether receiving a reward increases recall but also provides more specific information on the processes that are improved by explicit reward.
Experiment 1 A commonly used procedure to investigate the influence of reward on behavior is to establish a fairly long baseline without reward and then to make the reward contingent upon the occurrence of the response. The influence of the increased incentive is assessed by comparing baseline responses with rewarded responses. Because this is a commonly used procedure, this basic design was used in Experiment 1. Method Subjects. Thirty children (15 with learning disabilities and 15 without learning disabilities) were selected from three schools in middle Tennessee. The two groups were matched for age (M = 9.87; range, 9.41 to 10.67 years), sex (2 girls and 13 boys), and IQ based on the Otis-Lennon intelligence test (disabled, M = 96.7, range, 79 to 114; nondisabled, M = 96.9, range, 80 to 113). The IQs were matched within 3 points of each other. All children were White. The children with disabilities were classified according to state guidelines. The major basis for classifying children as disabled was a discrepancy between expected and actual academic performance. In spite of normal IQs, children with learning disabilities had received low grades and were 2 or 3 years behind their expected grade level. On the basis of the total score on the California Achievement test, disabled students were 1.71 years (range,
Downloaded by [University of Iowa Libraries] at 08:31 19 April 2015
450
The Journal of General Psychology
- 1.01 to - 2.83 years) behind expected achievement. Disabled children were behind expected performance in reading (M = - 2.20, range, -1.97 to - 2.34 years) and mathematics (M = - 2.01, range -1.97 to - 2.34 years). Nondisabled children were slightly ahead in overall achievement (M = .52; range, .16 to .80 years), reading (M = .53; range, 0 to 1.00 years), and mathematics (M = .62; range, .23 to 1.11 years). Only children with learning deficits that did not appear to be associated with cultural deprivation or mental retardation were included. Children with excessive disturbances of balance, incoordination, motor activity, or with a history of seizures, speech deficits, or emotional problems were excluded. At the time of testing, disabled students and nondisabled students were attending the same schools; disabled students were in special classes designed to correct their disabilities. Materials and procedure. The materials and procedure used were similar to those reported previously (Bauer, 1979). Common nouns from the Thorndike-Lorge (1944) list were randomly assigned to 40 lists of 10 words each. The lists were formed so that there were low intralist associations, and the words in each list did not belong to a particular category. The lists were recorded on cassette tape in a monotone voice at the rate of one word per 1.5 s. Each word was presented only once to each child. The tape recorder was turned off immediately after the last word of each list, and the sound produced by turning the recorder off served as the cue for recall. The intertrial interval was 30 ± 5 s, depending on the recall rate of the child. The next trial was presented when no more words could be recalled voluntarily or when asked for by the experimenter. The children were tested individually in a quiet room in the school building. The were seated at a table with the experimenter seated behind and slightly to the side of the child. Before the first testing session, the following instructions were read to the children: I am trying to determine your memory for words. I will playa tape and you will hear a list of words with 10 words on each list. After the last word in each list, I will tum the machine off. When you hear the machine go off, your job is to tell me all the words you can remember from the list. Don't be afraid to guess, and you can recall the words in any order. After you tell me all the words you can remember, I will tum the tape on and, a few seconds later, the next list will be given.
The experimenter then summarized the instructions, and four practice trials were given. Any procedural errors were corrected during the practice trials, and additional trials were given if the child did not comply with the instructions. Before the start of testing, the child was once again told to recall the words in any order and was encouraged to guess.
Bauer & Peller-Porth
451
Downloaded by [University of Iowa Libraries] at 08:31 19 April 2015
The words recalled on each of the 15 trials were recorded on paper, and after the session, the mean number of words correctly recalled by each child during the total session was determined. The mean number of words recalled per trial by each child served as the baseline for administering the tokens in the second session. Four to 5 days after completing the first session, the same subjects were tested in immediate free recall with tokens. Before testing, the following instructions were read to each child: This time you will be given tokens for recalling more words than you did last time. Each token is worth 5¢. For each list, I will give you one token for recalling one more word than the first time you were tested, two tokens for recalling two words better, three tokens for recalling three words better, and so on. Since you will be given 15 lists to recall, you could earn as much as $5.00. The more words you recall, the more tokens you will be given.
Each child was then given 15 more immediate-free-recall trials and, except for the tokens, the procedure was the same as in the first session. The tokens were given to the child immediately after each trial. Recalling fewer words per trial than the mean number recalled during the first session did not result in a loss of tokens.
Results Figure 1 shows the mean percentage of correctly recalled words averaged across trials in Sessions 1 and 2 as a function of serial positions by learningdisabled and nondisabled groups. The difference between the mean percentage of words recalled by the two groups at each serial position for each incentive condition is shown in Figure 2. The mean percentage recalled by each child at each serial position was analyzed by a 2 x 2 x 10 (Subject x Session x Serial Position) mixed analysis of variance (ANOVA). This analysis showed that recall was significantly higher by students without learning disabilities (M = 36.33%) than recall by students with learning disabilities (M = 29.67%), F(l, 28) = 7.62, p < .001 (p < .05 was considered to be significant for all statistics reported). However, a significant Subject x Serial Position interaction, F(9, 252) = 3.32, p < .001, and inspection of Figures 1 and 2 indicate that the difference between disabled and nondisabled groups was primarily due to the lower primacy effect by learning-disabled children. In support of this suggestion, trend analysis showed that the linear, F( 1, 596) = 355.20, p < .001, and the quadratic, F(l, 596) = 309.87, p < .001, components for the Subject x Serial Position interaction were significant. The mean percentage of words recalled by each child on the first three and on the last three serial positions was used to estimate primacy and regency effects, respectively. A Thkey test showed that recall on the first three serial
452
The Journal of General Psychology
100
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80
Downloaded by [University of Iowa Libraries] at 08:31 19 April 2015
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SERIAL POSITION FIGURE 1. Mean percentage of words correctly recaUed by learningdisabled (upper panel) and nondisabled (lower panel) children with and without monetary reward as a function of serial position.
Bauer & Peller-Porth
453
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The Journal of General Psychology Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/vgen20
The Effect of Increased Incentive on Free Recall by Learning-Disabled and Nondisabled Children a
Richard H. Bauer & Verna Peller-Porth
a
a
Department of Psychology , Middle Tennessee State University , USA Published online: 06 Jul 2010.
To cite this article: Richard H. Bauer & Verna Peller-Porth (1990) The Effect of Increased Incentive on Free Recall by Learning-Disabled and Nondisabled Children, The Journal of General Psychology, 117:4, 447-461, DOI: 10.1080/00221309.1990.9921150 To link to this article: http://dx.doi.org/10.1080/00221309.1990.9921150
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or
indirectly in connection with, in relation to or arising out of the use of the Content.
Downloaded by [University of Iowa Libraries] at 08:31 19 April 2015
This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/terms-and-conditions
The Journal of General Psychology. J17(4),447-462
Downloaded by [University of Iowa Libraries] at 08:31 19 April 2015
The Effect of Increased Incentive on Free Recall by Learning-Disabled and Nondisabled Children RICHARD H. BAUER VERNA PELLER-PORTH Department of Psychology Middle Tennessee State University
ABSTRACT. Immediate free recall by learning-disabled and nondisabled children was compared under two incentive conditions. Recall of the first few words of each list by disabled children and younger nondisabled children was lower than that by older nondisabled children, and receiving a monetary reward increased early list item recall by older disabled and nondisabled learners. These findings suggest that elaborative encoding processes, such as rehearsal, are impaired in younger disabled and nondisabled children and that receiving a reward increased elaborative encoding by older children. Similar recall of the last few list items by all groups suggests that attention and immediate memory are comparable in disabled and nondisabled children of different ages. Receiving a reward increased recall of the last few list items by younger disabled and nondisabled children, suggesting that a reward increased attention, immediate memory, or both, in these groups. Because receiving a reward increased recall equally in all groups, lower motivation did not appear to be responsible for the lower recall by younger nondisabled children and learning-disabled children.
CHILDREN WITH LEARNING DISABILITIES perform at a lower level than do nondisabled children across a broad spectrum of behaviors (e.g., Cruickshank & Hallahan, 1975; Parrill-Burnstein, 1981; Swanson, 1987). Because many behavioral deficits are found in children with learning disabilities, a common factor may be responsible. Intelligence is, by definition, not lowered in disabled students, and for this reason, differences in intelligence can be excluded. Adequate motivation is necessary for high performance, and if there is a single underlying basis for learning disabilities, motivation may be the important factor. However, very little research has been devoted to examining the role of motivation in performance of the learning disabled. 447
Downloaded by [University of Iowa Libraries] at 08:31 19 April 2015
448
The Journal of General Psychology
Studies on the influence of explicit incentives on children with and without learning disabilities have reported conflicting results. Without explicit incentives, discrimination learning is slower in disabled than in nondisabled learners, but with explicit incentives acquisition rates by both groups are similar (Blair, 1972; Shores, 1969). Thus, without explicit reward, children with learning disabilities may be less motivated. However, receiving a monetary reward increased paired-associate learning and serial recall of drawings by students with and without learning disabilities to about the same degree (Goyen & Lyle, 1971; Haines & Torgesen, 1979), suggesting that incentives increased motivation of both groups. Torgesen and Houck (1980) found that, without monetary reward, digit recall by nondisabled children and learning-disabled children who had adequate digit recall decreased across trials and that monetary reward attenuated the decrease across trials. These results suggest that without additional incentives, motivation decreased across trials and that receiving monetary reward maintained a higher level of motivation. When no incentives were given to children with learning disabilities that had low digit recall, there was no significant decrease across trials, and reward had no significant effect on recall. Information processing deficits are thought to be an important component of learning disabilities (for a review, see Bauer, 1987), and lower-thannormal motivation may play an important role in impairing information processing. Therefore, results obtained by comparing information processing in children with and without learning disabilities when no additional incentives are provided and when explicit incentives are provided would have important implications for understanding learning disabilities. The major purpose of the present study was to compare information processing by children with and without learning disabilities under different incentive conditions. Because the information processing that occurs in immediate free recall is well defined (e.g., Atkinson & Shiffrin, 1971; Bauer, 1979), the immediate-free-recall task was used to investigate the influence of incentives. In immediate free recall, the first few items of each list are given more elaborative encoding, such as cumulative rehearsal and subjective reorganization, than are later items of each list. The more permanent storage produced by elaborative encoding is primarily responsible for the high recall of early list items (the primacy effect). Subjects recall the less permanently stored last few list items before recalling more permanently stored early list items because
The research was funded by the Middle Tennessee State University Program. We thank Rupert Klaus, Jerry Nash, and the teaching and administrative staff of the Murfreesboro and Hickman County school systems for their assistance in conducting this research. Requests for reprints should be sent to Richard H. Bauer, Department of Psychology, MiddLe Tennessee State University, Murfreesboro, TN 37132.
Downloaded by [University of Iowa Libraries] at 08:31 19 April 2015
Bauer & Peller-Porth
449
they are apparently aware that early recall of less permanently stored information increases recall of the last few items without interfering with recall of more permanently stored information. Recall of the last few items before recall of earlier items, attention, and immediate memory are primarily responsible for the high recall of the last few list items (the recency effect). The information processing that occurs in immediate free recall provides an opportunity to examine the influence of explicit reward on three major processes. Increased recall of the first few list items would suggest that incentives increase elaborative encoding. Higher recall of the last few list items on rewarded trials would suggest an increase in (a) attention and immediate memory, (b) the number of the last few items recalled before early item recall, or (c) both. To determine whether recall of the last few items was altered by monetary incentives, recall order was examined under no-incentive and incentive conditions. Thus, comparing performance of disabled and nondisabled groups in immediate free recall under no incentive and incentive conditions not only provides information concerning whether receiving a reward increases recall but also provides more specific information on the processes that are improved by explicit reward.
Experiment 1 A commonly used procedure to investigate the influence of reward on behavior is to establish a fairly long baseline without reward and then to make the reward contingent upon the occurrence of the response. The influence of the increased incentive is assessed by comparing baseline responses with rewarded responses. Because this is a commonly used procedure, this basic design was used in Experiment 1. Method Subjects. Thirty children (15 with learning disabilities and 15 without learning disabilities) were selected from three schools in middle Tennessee. The two groups were matched for age (M = 9.87; range, 9.41 to 10.67 years), sex (2 girls and 13 boys), and IQ based on the Otis-Lennon intelligence test (disabled, M = 96.7, range, 79 to 114; nondisabled, M = 96.9, range, 80 to 113). The IQs were matched within 3 points of each other. All children were White. The children with disabilities were classified according to state guidelines. The major basis for classifying children as disabled was a discrepancy between expected and actual academic performance. In spite of normal IQs, children with learning disabilities had received low grades and were 2 or 3 years behind their expected grade level. On the basis of the total score on the California Achievement test, disabled students were 1.71 years (range,
Downloaded by [University of Iowa Libraries] at 08:31 19 April 2015
450
The Journal of General Psychology
- 1.01 to - 2.83 years) behind expected achievement. Disabled children were behind expected performance in reading (M = - 2.20, range, -1.97 to - 2.34 years) and mathematics (M = - 2.01, range -1.97 to - 2.34 years). Nondisabled children were slightly ahead in overall achievement (M = .52; range, .16 to .80 years), reading (M = .53; range, 0 to 1.00 years), and mathematics (M = .62; range, .23 to 1.11 years). Only children with learning deficits that did not appear to be associated with cultural deprivation or mental retardation were included. Children with excessive disturbances of balance, incoordination, motor activity, or with a history of seizures, speech deficits, or emotional problems were excluded. At the time of testing, disabled students and nondisabled students were attending the same schools; disabled students were in special classes designed to correct their disabilities. Materials and procedure. The materials and procedure used were similar to those reported previously (Bauer, 1979). Common nouns from the Thorndike-Lorge (1944) list were randomly assigned to 40 lists of 10 words each. The lists were formed so that there were low intralist associations, and the words in each list did not belong to a particular category. The lists were recorded on cassette tape in a monotone voice at the rate of one word per 1.5 s. Each word was presented only once to each child. The tape recorder was turned off immediately after the last word of each list, and the sound produced by turning the recorder off served as the cue for recall. The intertrial interval was 30 ± 5 s, depending on the recall rate of the child. The next trial was presented when no more words could be recalled voluntarily or when asked for by the experimenter. The children were tested individually in a quiet room in the school building. The were seated at a table with the experimenter seated behind and slightly to the side of the child. Before the first testing session, the following instructions were read to the children: I am trying to determine your memory for words. I will playa tape and you will hear a list of words with 10 words on each list. After the last word in each list, I will tum the machine off. When you hear the machine go off, your job is to tell me all the words you can remember from the list. Don't be afraid to guess, and you can recall the words in any order. After you tell me all the words you can remember, I will tum the tape on and, a few seconds later, the next list will be given.
The experimenter then summarized the instructions, and four practice trials were given. Any procedural errors were corrected during the practice trials, and additional trials were given if the child did not comply with the instructions. Before the start of testing, the child was once again told to recall the words in any order and was encouraged to guess.
Bauer & Peller-Porth
451
Downloaded by [University of Iowa Libraries] at 08:31 19 April 2015
The words recalled on each of the 15 trials were recorded on paper, and after the session, the mean number of words correctly recalled by each child during the total session was determined. The mean number of words recalled per trial by each child served as the baseline for administering the tokens in the second session. Four to 5 days after completing the first session, the same subjects were tested in immediate free recall with tokens. Before testing, the following instructions were read to each child: This time you will be given tokens for recalling more words than you did last time. Each token is worth 5¢. For each list, I will give you one token for recalling one more word than the first time you were tested, two tokens for recalling two words better, three tokens for recalling three words better, and so on. Since you will be given 15 lists to recall, you could earn as much as $5.00. The more words you recall, the more tokens you will be given.
Each child was then given 15 more immediate-free-recall trials and, except for the tokens, the procedure was the same as in the first session. The tokens were given to the child immediately after each trial. Recalling fewer words per trial than the mean number recalled during the first session did not result in a loss of tokens.
Results Figure 1 shows the mean percentage of correctly recalled words averaged across trials in Sessions 1 and 2 as a function of serial positions by learningdisabled and nondisabled groups. The difference between the mean percentage of words recalled by the two groups at each serial position for each incentive condition is shown in Figure 2. The mean percentage recalled by each child at each serial position was analyzed by a 2 x 2 x 10 (Subject x Session x Serial Position) mixed analysis of variance (ANOVA). This analysis showed that recall was significantly higher by students without learning disabilities (M = 36.33%) than recall by students with learning disabilities (M = 29.67%), F(l, 28) = 7.62, p < .001 (p < .05 was considered to be significant for all statistics reported). However, a significant Subject x Serial Position interaction, F(9, 252) = 3.32, p < .001, and inspection of Figures 1 and 2 indicate that the difference between disabled and nondisabled groups was primarily due to the lower primacy effect by learning-disabled children. In support of this suggestion, trend analysis showed that the linear, F( 1, 596) = 355.20, p < .001, and the quadratic, F(l, 596) = 309.87, p < .001, components for the Subject x Serial Position interaction were significant. The mean percentage of words recalled by each child on the first three and on the last three serial positions was used to estimate primacy and regency effects, respectively. A Thkey test showed that recall on the first three serial
452
The Journal of General Psychology
100
LD
--
_---e
80
Downloaded by [University of Iowa Libraries] at 08:31 19 April 2015
I-
60
No Incentive Incentive
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SERIAL POSITION FIGURE 1. Mean percentage of words correctly recaUed by learningdisabled (upper panel) and nondisabled (lower panel) children with and without monetary reward as a function of serial position.
Bauer & Peller-Porth
453
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