Associative interference as a function of amount of first-task practice and stimulus similarity

JOURNAL

OF EXPERIMENTAL

CHILD

Associative of

interference

First-Task

LOUIS

California

20%211 (1968)

as a Function

Practice

The

6,

PSYCHOLOGY

and

Stimulus

of Amount Similarity

E. PRICE

University

of New

Mexico

NANCY J. COBB State College at Los Angeles AND

J. MORIN

NANCY University

of

Massachusetts

The effects of first-task practice and stimulus similarity on transfer in a verbal paired-associate task were evaluated under the A-B, A-Br, and A-B, A-C paradigms relative to an A-B, D-C control using elementary school children as Ss. In agreement with previous findings, both the A-C and A-Br paradigms resulted in associative interference, with the effect more pronounced in the latter paradigm. An increase in stimulus similarity increased task difficulty in both the acquisition and transfer tasks but did not differentially affect performance under the transfer paradigms. Amount of firsttask practice interacted with paradigms in that associative interference decreased in the A-C paradigm and showed little change in the A-Br paradigm with an increase in first-task practice. In a second experiment the same design and procedure were followed with the exception that amount of first-task practice was varied according to predetermined numbers of trials rather than criteria of mastery as in the first study. The results for transfer performance essentially paralleled those of the first experiment, differing only in failing to obtain a significant interaction of paradigms with amount of practice.

Investigations of transfer in verbal paired-associate learning have, in general, found evidence for most associative interference in the A-B, A-Br paradigm, in which the stimuli and responses of the first task are repaired in the second task. Associative interference has also been obtained in the A-B, A-C paradigm where new responses must be learned to the original stimuli (Besch and Reynolds, 1958; Jung, 1962; Postman, 1962; Twedt and Underwood, 1959). Increases in first-task practice should increase the strength of previously correct responses and thereby increase the amount of associative 202

ASSOCIATIVE

INTERFERENCE

203

interference observed in these paradigms. In general, this has been the trend for the A-Br paradigm (Jung, 1962; Postman, 1962; Winnick, 1966), although inconsistent findings have been reported for the A-C paradigm, with Spiker (1960) and Spence and Schulz (1965) observing an increase in interference with increased first-task practice and with no differences in net transfer with increases in Task-l practice reported by Jung (1962) and Postman (1962). Increasing stimulus similarity is a second way of creating greater competition with the correct response in the second task, and thus of producing increased associative interference. The responses competing with the correct response are not only the previously correct response from the first task, but also generalized tendencies established in the first task as the correct response was learned, and generalized tendencies established with the learning of the correct response in the second task. Increasing stimulus similarity should increase the strength of the latter two sources of competition, i.e., the generalized responses, while increasing first-task practice should increase the first source. The amount of associative interference occurring from these sources would not be expected to be equal for the A-Br and A-C paradigms. Since the same responses occur in both tasks in the A-Br paradigm, strong competition from generalized first-task responses would exist at the outset of the second task, and as learning progressed these generalized tendencies would be further strengthened. In the A-C paradigm this initial competition would not be present. Moreover, in the A-Br paradigm, the previously correct response is present and rewarded, although to a different stimulus, thus offering additional competition as a generalized tendency which is further strengthened in the second task. This additional source of competition is not present in the A-C paradigm since the previously correct response does not appear in the second task. Thus an interaction of stimulus similarity with paradigms would be expected in which the difference in associative interference occurring under the A-Br and A-C paradigms would be greater under the condition of high stimulus similarity than under that of low similarity. Although one study (Saravo and Price, 1967) attempted to demonstrate this relationship, the results were negative. Their failure to obtain either a significant effect for simnarity or an interaction of similarity with transfer paradigms could be due to the manner in which similarity was manipulated. Increases in stimulus similarity were accomplished by increasing the number of common letters in nonsense syllables; however, the first letter of each syllable always differed. The results of a study by Gaeth and Allen (1966) suggest that sixth-grade children, the age of the Ss in the Saravo and Price study, are able to respond to the critical letters

204

PRICE,

COBB,

AND

M!?RIN

differing between nonsense syllables which otherwise are comprised of identical elements when the position of the former does not vary from one syllable to the next. Thus it is quite likely that the presence of this distinctive cue attenuated the effects of similarity. The purpose of the present investigation was to further study the effects of first-task practice and stimulus similarity as they relate to associative interference under the A-B, A-Br and A-B, A-C paradigms when evaluated against an A-B, D-C control. Highly integrated responses of two-digit numbers were used to minimize the contribution of response learning in the A-Br paradigm and thus allow a less complicated comparison of associative interference under this and the A-C paradigm. Two-dimensional colored forms served as the stimuli of the pairedassociate tasks, thus lessening the possibility of selective attention to a single, distinctive aspect of the stimulus, which could attenuate the effects of stimulus similarity. With increases in both the level of stimulus similarity and amount of first-task practice, it was expected, on the basis of increased response competition, that the amount of associative interference would also increase. EXPEHMENT

I

Method Subjects. Forty-eight children were selected from the third, fourth, fifth, and sixth grades of three elementary schools in Western Massachusetts.l The average age for each group was approximately 10 years. Stimuli and apparatus,. The stimuli consisted of al/,- X 21/2-inch color forms cut out of sample colors from the Benjamin Moore Paint Company and pasted on white plastic cards for presentation on a Hunter Card Master. The high similarity condition consisted of forms which had saturations of three colors: pink, orange, and brown. The low similarity condition consisted of forms of different colors and, in any one list, no color appeared more than once.” The response members were numbers ‘The authors wish to thank Mr. James Cebula, Principal, Marks Meadow School, Amherst, Massachusetts; Mr. Richard W. Rege, Principal, James Selser Memorial School; Mr. John L. Fitzpatrick, Superintendent of Schools; and Miss Sophie J. Chumura, Assistant Superintendent in Charge of Elementary Education in Chicopee, Massachusetts, for their cooperation during the course of this study. ‘The specific colors can be found by matching the following identification numbers with the colors found in the Universal Color System of the Benjamin Moore Paint Company. For the condition of high similarity the identification numbers of the colors used are 332, 4-39, 4-32, 5-32, 4-3, 5-6, 4-72, and 5-72. For the condition of low similarity the identification numbers are 2-8, 3-56, 5-32, 6-40, S-40, 13-24, 19-24, and 19-45.

ASSOCIATIVE

INTERFERENCE

205

ranging from 1 to 20, exclusively. Responses were selected for each list such that (a) each list had the same number of odd numbers as even numbers, (b) numbers with a fixed ratio were not used and, (c) numbers which rhymed were excluded. Each S learned two lists of paired associates, List 1 (acquisition task) and List 2 (transfer task) which were the same for all Ss under each condition of stimulus similarity. Each list consisted of six stimulusresponse pairs, with two pairs representing each of the three paradigms. To control for possible differential difficulty of the List-2 pairs, three counter-balancing forms of List 1 were constructed which de&red the pairs in the second task representing each of the paradigms. Design. Two levels each of amount of first-task practice and stimulus similarity were manipulated between subjects. Specifically, four conditions were defined t.hrough a factorial combination of high and low conditions of practice and high and low stimulus similarity. Three counterbalancing forms for item difficuIty of the pairs representing each of the paradigms constituted a third between subjects variable. Paradigms were manipulated within subjects. Procedure. The S was seated in front of the apparatus and told he could play a color game in which colors would appear in the left window of the apparatus and numbers would be shown in the right window. The S was instructed that each coIor had its own number, and that he had to guess the number that would be shown in the right window as each color was presented alone in t,he left window. During the first trial, S was told not to anticipate the number but to wait until he saw the number and then pronounce it. A further inquiry was made as to whether S understood the instructions and was ready to begin the task. The 8s were given practice on the first task until they reached a criterion of five correct of six responses on any trial or to a criterion of two consecutive errorless trials, defining low and high practice, respectively. Task 2 was begun immediately following compIet,ion of the first task and S was instructed to play the game in the same manner as before. All 8s were given 10 trials on Task 2. The anticipation interval, joint presentation interval, and interstimulus interval were 6, 6, and 2 seconds, respectively, for both Task 1 and Task 2. Three different orders of each list were given to minimize serial associations. Results Task 1. An analysis of variance of the mean number of trials through criterion yieIded significant effects for both similarity, F(1,36) = 46.40, p < .OOl, and for amount of practice, F(1,36) = 30.29, p < .OOl. The high-similarity condition required more trials to reach criterion than the

206

PRICE,

COBB,

AND

MORIN

low-similar&y condition and, as would be expected, more trials were necessary to reach the more stringent criterion of practice than the less stringent criterion. Under the condition of high stimulus similarity, means of 11.17 and 20.41 trials were required to reach the criteria defining low and high practice, respectively. Under conditions of low similarity, means of 7.92 and 11.42 trials were required to reach these criteria. The interaction of similarity with amount of practice was not significant, F(1,36) = .55, p > .05. Task 6. Figure 1 shows the overall transfer effects for each paradigm. Consistently more correct responses were given throughout the course of

.-. D-C .--. ,--e-e-.

OV

A-C A-Br

9-10 BLOCKS

OF TWO TRIALS

FIQ. 1. Mean number of correct responses per blocks of two trials for each of three transfer paradigms.

learning under the D-C paradigm than under the A-C; and with the cxception of a single inversion in the initial trials, the latter was consistently superior to the A-Br. Thus both paradigms resulted in negative transfer when compared with a D-C control, with more interference evident in the A-Br. Table 1 presents the means for the total number of correct responses on the transfer task for the three paradigms under each of the combinations of high or low similarity with high or low practice. An analysis of variance of the number of correct responses in Task 2 revealed both a significant effect for paradigms, F(2,72) = 10.36, p < -001, and a significant interaction of paradigms with trials, F(18,648) = 1.96, p < .05, in which performance under the three paradigms progressively diverged with increased trials on the transfer task.

ASSOCIATIVE

207

INTERFERENCE

The effect of similarity was confirmed for each paradigm, with more correct responses given under the low-similarity condition than under the high-similarity condition. Differences in performance under the two conditions of stimulus similarity progressively increased with increased trials in the second task. Both the main effect for similarity and the interaction of similarity and trials were significant, F(1,72) = 13.47, EXPERIMENT

I:

MEAN

High Paradigm A-Br A-C D-C

High

TABLE 1 TOTAL CORRECT

RESPONSES

similarity

practice

Low

30.00 36.25 37.25

IN TRANSFER Low

High

practice

similarity

practice 36.25 42.00 42.75

28.75 29.25 34.00

Low

practice 35.00 33.00 43.25

p < .OOl and F(9,324) = 3.83, p < .OOl, respectively. In addition, for each level of similarity, both the A-C and A-Br paradigms resulted in associative interference with respect to the D-C control, the A-Br demonstrating more interference than the A-C in each case. The interaction of similarity and paradigms, however, was not significant, F(2,72) = .72, p > .05. The main effect for amount of practice was not significant, F(1,36) = 1.94, p > .05. The interaction of amount of first-task practice and para-

.-. .-. .-----mm. 0’

I LOW

I HIGH FIRST-LIST

FIQ. 2. Mean total number digms as a function of amount

D-C A-C A-B,

of correct of first-list

PRACTICE

responses practice.

for

each

of three

transfer

para-

208

PRICE,

COBB,

AND

MORIN

digms, however, was significant, F(2,72) = 3.75, p < .05. Increased practice only slightly increased performance on the D-C paradigm, while markedly improving performance on the A-C paradigm. Performance on the A-Br paradigm showed no appreciable improvement with increased first-task practice (see Fig. 2). Discussion

In agreement with other studies which used a control for nonspecific transfer, associative interference occurred in both the A-C and A-Br paradigms, with most interference evident in the latter paradigm (Besch and Reynolds, 1958; Jung, 1962; Postman, 1962; Twedt and Underwood, 1959). Though increased stimulus similarity significantly lowered overall performance, the extent of associative interference was not a function of level of similarity. Competition from generalized responses in the second task would be greater for all paradigms under the condition of high similarity, however more interference might be expected in the A-Br paradigm since here these generalized tendencies would strengthen competing first-task tendencies. It could be that any increased competition in the A-Br paradigm was offset by entering the second task with initially stronger correct tendencies for each pair, i.e., one of the generalized tendencies which would be stronger to a more similar stimulus was correct when given to that stimulus in the second task. Though amount of first-task practice did not produce a significant overall effect on performance in the second task, the interaction of amount of practice with paradigms was significant. With increased first-task practice, performance on the A-C paradigm improved, while that on the D-C and A-Br paradigms remained relatively unchanged. Jung (1962) noticed a similar trend in the A-C paradigm with increased first-task practice and Postman (1962) also found a tendency toward improved performance on the A-C paradigm as first-task practice was increased from one errorless trial to 50% overlearning: as in the present study, however, the A-C paradigm never resulted in positive transfer. These findings are in contrast to those of Spiker (1960) and Spence and Schulz (1965) where increased training on the first task led to an increase in interference under the A-C paradigm. EXPERIMENT

II

Both Spiker (1960) and Spence and Schulz (1965) presented the first task for a set number of trials which differed between groups of 8s whereas Postman (1962) and Jung (1962) trained different groups of Ss to various levels of mastery at the first task. Associative interference was found to increase in the A-C paradigm with increased first-task

ASSOCIATIVE

INTERFERENCE

practice only with the former method of varying amount an effort to replicate this effect, Exp. II was conducted design as the first experiment, but differing from the first of first-task practice was defined in terms of different trials as opposed to different criteria of task mastery.

209 of practice. In with the same in that amount set numbers of

Method

Forty-eight children from the third, fourth, fifth, and sixth grades participated in the study. The children were drawn from the same elementary schools as were the 8s in Exp. I and had a mean age of approximately 10 years in each group. The stimuli, apparatus, and procedure were the same as in Exp. I with the following exception. For the low and high conditions of practice, 5s received either 10 or 20 trials, respectively, on Task 1 under the condition of high stimulus similarity and either five or 10 trials under low stimulus similarity. These set numbers of trials were approximately equivalent to the numbers of trials required to reach the respective criteria of the first study. Task 2 was begun immediately following completion of the first task and, as in Exp. I, all Ss were given 10 trials on Task 2. In all other respects the procedure was identical to that of the first experiment. Results

and Discussion

Task 1. In an analysis of the mean total correct responses, both stimulus similarity and amount of first-task practice proved significant, F(1,36) = 88.53, p < .OOl and F(1,36) = 82.64, p < .OOl, respectively. More correct responses were given under the condition of low stimulus similarity than under high similarity. In addition, the mean total correct, responses varied directly with amount of first-task practice. The interaction of similarity with amount of practice was also significant, F(1,36) = 4.67, p < .05, and suggests that performance under conditions of high similarity is affected more by amount of practice than performance under low similarity. Task d. Table 2 presents the means for the total number of correct responses for the three paradigms under each of the four combinations of high and low stimulus similarity and high and low amounts of first-task practice. An analysis of variance with similarity, amount of practice, and counterbalancing forms as between subjects variables and paradigms and trials as within subjects comparisons was performed on this data. The main effect for paradigms was highly significant, F(2,72) = 8.92, p < .OOl, with more correct responses given under the D-C paradigm than under the A-C paradigm and with performance under the latter superior to performance under the A-Br. The interaction of paradigms with trials

210

PRICE,

COBB,

AND

MORIN

was also significant, F(18,648) = 2.20, p < .Ol, the difference among paradigms increasing with increased trials. Stimulus similarity significantly retarded performance, F (1,36 = 14.15, p < .OOl, and interacted with trials such that the retarding effect of high similarity became more pronounced as learning in the second task progressed, F(9,324) = 2.66, p < .Ol. The interaction of similarity with paradigms again failed to reach significance. Neither the main effect for amount of practice, nor the interaction of practice with any other variable reached significance. No other main effects or interactions were significant. The results of the second experiment essentially parallel those of the first. As in the first experiment, performance under the transfer paradigms decreased in the order of D-C superior to A-C which, in turn, was superior to A-Br. This order is also consistent with the findings of most studies TABLE EXPERIMENT

II: MEAN

TOTAL

2

CORRECT

High similarity

RESPONSES

IN TRANSFER

Low similarity

Paradigm

High practice

Low practice

High practice

Low practice

A-Br A-C D-C

30.00 34.00 34.75

27.75 29.50 32.25

36.50 38.25 42.75

34.00 35.75 40.00

comparing these paradigms (e.g. Besch and Reynolds, 1958). Thus associative interference was demonstrated in both experiments. Also, in both experiments performance under the three paradigms significantly diverged over trials in the second task. Both similarity and amount of practice significantly affected first-task performance, whereas only similarity proved to exert a significant effect on transfer-task performance. These effects were consistent from one experiment to the next. The major difference between the experiments with regard to transfer-task performance was the failure of the practice X paradigms interaction to reach significance in the second experiment. Although associative interference under the A-C paradigm was only found to decrease when practice was varied in terms of trials to criteria of task mastery, this variable does not seem to account for the difference in the results of these two experiments or of others since increased interference in the A-C paradigm with an increase in previously determined numbers of trials was not found in the second study as would be expected on the basis of Spiker’s results. It seems more likely that other variables such as differences in the levels of practice varied under either procedure, the nature of stimuli, of re-

ASSOCIATIVE

INTERFERENCE

211

sponses, etc. are responsible for the obtained difference for the A-C paradigm. Certainly there is a need for greater similarity between laboratories in the materials and procedures used in parametric investigations of this nature. REFERENCES N. F., AND REYNOLDS, W. F. Associative interference in verbal paired associate learning. Journal of Experimental Psychology, 1958, 55, 554-558. GAETH, J. H., AND ALLEN, D. V. Effect of similarity upon learning in children. Journal of Experimental Child Psychology, 1966,4 381390. JUNG, J. Transfer of training as a function of degree of first-list learning. Journul of Veerbal Learning and Verbal Behavior, 1962. 1, 197-199. POSTMAN, L. Transfer of training as a function of experimental paradigm and degree of first-list learning. Journal of Verbal Learning and Verbal Behavior, 1962, 1, 109-118. SARAVO,A. C., AND PRICE, L. E. Associative transfer in verbal paired-associate learning as a function of stimulus similarity. Psychonomic Science, 1967, 8, 315317. SPENCE, J. T. AND SCHULZ, R. W. Negative transfer in paired-associate learning aa a function of first-list trials. Journal of Verbal Learning and Verbal Behavior, 1965, 4, 397400. SPIRER, C. C. Associative transfer in verbal paired-associate learning. Child DeveG opment, 1960, 31, 73-87. TWEDT, H. M., AND UNDERWOOD, B. J. Mixed vs. unmixed lists in transfer studies. Journal of Experimental Psychology, 1959, 58, 111-116. WINNICK, W. A. Effect of instructional set and amount of first learning on negative transfer. Journal of Experimental Psychology, 1966, 71, 920-923. BESCH,