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Journal of Educational Psychology1965, Vo l. 56, N o. 4, 208-216

MEMORY AND THE FEELING-OF-KNOWINGEXPERIENCE

1

J. T. HART1

Stanford University

To evaluate the accuracy of feeling-of-knowing experiences 2 in-vestigations are repo rted. Both experiments (Ns of 22 and 16, respec-tively) show the phenomenon to be a relatively accurate indicator ofmemory storage, as measured by the ability of Ss to predict recog-nition failures and successes for items they cannot recall. The resultsare discussed in terms of the utility of a memory-monitoring processfor the efficient functioning of a fallible storage and retrieval system.

Even when unable to answer difficultquestions, people are not completelyblank. Usually they have definite feel-ings about whether they know ordo not know the absen t answers. Feel-ings of knowing can sometimes bevery strong; a person will feel that anelusive memory is close, very close—right on the tip of his tongue. Tip-

of-the-tongue experiences and feelingsof knowing of lesser intensities arevery common, occurring every daywith many types of memory materials:names, dates, telephone numbers,addresses, faces, places, etc.

It is not surprising then that thetip-of-the-tongue experience has beenrecognized by psychologists for many

years; nor is it surprising that a fewinvestigations of the experience havebeen conducted. William James (1950),who seems to have had something wiseto say about everything psychological,discussed the tip-of-the-tongue phe-nomenon at length (pp. 251-264).Woodworth and Schlosberg (1954)have summarized the early investiga-

IThis investigation was completed while

the author was on a United States PublicHealth Service predoctoral research fellow-ship. The investigation constitutes a portionof the author's PhD dissertation a t S tanfordUniversity.

I1 am indebted to Albert Hastorf,

Leonard Horowitz, and Karl Pribram forvaluable discussions about the planning

and results of this research.

tions of the phenomenon (pp. 719-721). These early investigations were,however, limited in several respects:(a) Only th e intense tip-of-the-tongueexperiences were studied, n ot th e moregeneral and ubiquitous feeling-of-know-ing experiences; (b ) the investigationswere unsystematic and nonquanti-tative, consisting mainly of collec-

tions of instances; and most im-portantly (c) the investigations didnot answer, nor even ask, what isperhaps the most important questionabout tip-of-the-tongue or feeling-of-knowing experiences—are they ac-curate? Instead, the early investiga-tors took the phenomenon as givenand tried to study how subjects re-trieved or searched for informationthey did not have but felt they knew.This retrieval problem is of considera-ble interest, bu t i t depa rts from thestudy of the feeling-of-knowing (FOK)phenomenon itself. Indeed, askinghow FOK memories are retrieved pre-supposes that the FOK experience isan acc urate indicator of w ha t is inmemory. This presupposition is testedin the following investigations.

EXPERIMENT I

Method

To answer the question about the accu-racy of FOK experiences it ie necessary tofind a research paradigm within which theexperiences can be produced and their

accuracy evaluated. Use was made of one208

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MEMOBY AND THE FEELING-OF-KNOWING 209

of the bestrestablished facts of verballearning—recognition exceeds reca ll. Peoplecan almost always recognize more answersthan they can produce. From this fact

the following recall-judgment-recognition(RJR) paradigm can be applied aa a way ofstudying the accuracy of FOK experiences:(a) give the subjects a test of recall and, forthose items they cannot answer, instructthem to make a judgment about whether ornot they feel they know the correct answerwell enough to recognize it among severalwrong alternatives; (b ) then give the sub-jects a multiple-choice recognition testcovering the same items that appeared in

the test of recall.If the FOK experience is an accurateindicator of memory storage, the subjectsshould do better on those recognition-testitems which they feel they know bu t cannotrecall than on those items which they feelthey do not know. Accuracy can be easilyassessed by comparing the proportion cor-rect on feeling-of-knowing (FK) item s withthe proportion correct on feeling-of-not-knowing (FK) items for each subject.

Both of the experiments reported in thispaper employed the same RJR two-stepprocedure. Experiment I differs fromExperiment II only in the number of ques-tions included in th e tes ts (60 and 75, respec-tively) and the kind of FOK judgments ob-tained from the subjects (dichotomous andgraded, respectively). The reasons forthese differences will be given after themethod and results of the first experimentare presented.

Materials

The questions used in the recall andrecognition tests were 50 general-informa-tion questions. An attempt was made torange widely over the humanities andsciences, choosing questions that would bemeaningful but not easy for the averageundergraduate. The basic criterion forinclusion was that a question have a singlecorrect answer. Three sample questionsare given below in multiple-choice form:

Which planet is the largestin our solar system?

a. Pluto b. Venus c. Ea rth d. JupiterHow many sides are there in a hexagon?

a. 8 b. 9 c. 6 d. 7Who wrote "The Tempest"?

a. Moliere b . Strindberg c. Jonsond. Shakespeare

Procedure

The experiment was administered to allsubjects in a single group. All 22 were Stan -

ford undergraduates who had signed up forthe experiment to fulfill a course require-ment in general psychology. When the sub-jects arrived, they were seated around alarge tab le; then instructions, including thefollowing, were read to them prior to thetest of recall:

"The main thing you will be doing in thisexperiment is answering questions. All thequestions are questions of fact. Althoughthe questions are not easy, they are abouttopics that may have been familiar to you

at one time. These questions do not consti-tute an intelligence test, and you are notexpected to answer all of the questionscorrectly. You will be given abou t 10 secondsto answer a question after I read it aloud.Do not make wild guesses but do writedown any answer you believe might be cor-rect. Also, do not at this time return toquestions that you have already passedover. You will be given a chance later to goover the questions again.

"I mentioned before that you are not ex-pected to answer every question correctly.Indeed the questions were chosen so thateveryone would be unable to answer somequestions the first time through. This wasdone because we are interested in yourfeelings about the questions for which youare unable to give a correct answer.

"Next to the answer box for every ques-tion there are two columns labeled 'Feelingof Knowing: Yes/No.' If you cannot supplyan answer to a question, make a check in

one of the columns adjacent to the blankanswer space. If you check the No column,that will indicate that you feel completelyblank about what the correct answer mightbe. If you check the Yes column, that willindicate you have a feeling that you knowthe correct answer even though you cannotremember it at the moment. The criterionquestion to ask yourself before checking theYes column is, 'Even though I don't re-member the answer now, do I know theanswer to the extent that I could pick thecorrect answer from among several wronganswers?' If your answer to this criterionquestion is 'yes,' check Column 1. If youranswer is 'n o, ' check Column 2.

"After you have finished all 50 questions,you will be given a second form of the test.On that form you will need to circle thecorrect answer among four possible an-swerB."

After these instructions were read to the

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210 J. T. HART

subjects, the experimenter proceeded toread the questions at a rate of approxi-mately 10-15 seconds per question. When the50 questions were completed, the answer

sheets were collected, and then the subjectswere given the multiple-choice form of theSO questions. On the recognition test eachsubject worked independently at his ownspeed, going over all 50 questions again. Thesubjects were instructed to answer everyquestion on the recognition test, even ifthey had to guess.

Results

Table 1 shows, as expected, thatmemory scores are higher for recogni-tion than recall. The questions wrongon the test of recall are categorizedinto errors and blanks. For the pur-poses of the experiment interest cen-ters on the questions left blank, sincethese were the questions that receiveda FOK judgment by the subjects. Theblanks are subdivided into those forwhich a FK or Yes judgm ent was madeand those for which a FK or No judg-ment was made.

Before looking at the data to assessthe accuracy of FOK judgments, a fewdefinitions are necessary. The mean-ing of a ^hit" or a "miss" differs forFK and FK items. A FK hit can bestraightforwardly defined as a correctmultiple-choice response on a question

TABLE 1RECALL AND RECOGNITION SCOBES

EXPERIMENT I

Tests

RecallCorrectIncorrect

ErrorsBlanks

F KF K

RecognitionCorrectIncorrect

u

26.623.4

5.218.28.2

10.0

39.810.2

SD

7.27.22 .46 .03 .34 .4

4 .94 .9

Note.—Fifty-item tests, N = 22.

previously left blank and judged FK(Yes); a F K miss would be an incorrectmultiple-choice response. For FK

blanks a h it would be the converse of aF K hit, since the subject who marks ablank F K (No) is saying th a t he doesnot feel he knows the correct answerand does not expect to recognize it onth e multiple-choice tes t. Consequently,a FK hit would be scored for a wrongmultiple-choice response and a FKmiss for a correct multiple-choice

response. Am biguity can be avoided ifit is remembered that the terms "hit"and "miss" apply to the accuracy ofthe F OK judgm ents, not to th e correct-ness of the multiple-choice responses.

For the overall test of the accuracyof the FO K judgm ents, FK hits shouldbe compared to FK misses. This com-parison clearly indicates that morerecall items judged FK are subse-quently gotten correct on the recogni-tion test than FK items. A sign test(Siegel, 1956) shows the results to bestatis tically significant (p < .001, onetailed). On the basis of these results,the FOK experience appears to be atleast a minimally accurate indicator ofmemory storage.

I t would be interesting to know if the

indicator is equally accurate for bothFK and FK judgments. Table 2 pre-sents the data for FK and FK hitsand misses. It can be seen immediatelythat the FK results are highly signifi-can t (p < .001, one tailed), suggest-ing that the FK indicator is an ac-curate predictor of what is in storage.However, th e F K portion of Table 2

shows th a t subjects are not so accuratein predicting what is not in storage(p > .05, one tailed); many subjectstend to correctly recognize answersthey did not feel they knew whiletaking the test of recall. If the f £indicato r were perfectly accu rate, mostof the subjects should have FK missproportions of about .25—the guessing

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MEMORY AND THE FEELING-OF-KNOWING 211

TABLE 2

FK AND FK PROPORTIONS DIVIDED INTO H I T S AND MISSES

EXPERIMENT I

Ss

1

2

3

4

5

6

7

89

10

11

FK

Hits

.86

.82

.88

.90

.50

1.001.00

.60.77

.88

.67

Misses

.14

.18

.12

.10

.60

.00

.00

.40

.23

.12

.33

B i t s

.25

.73

.33

.54

.88

.53

.64

.43.60

.80

.82

FK

Misses

.75

.27

.67

.46

.12

.47

.36

.57.40

.20

.18

5 s

12

13

14

15

1617

18

1920

21

22

FK

Hits

.94

.80

.89

.70

.75

.67

.62

.50.78

.62

.50

Misses

.06

.20

.11

.30

.25

.33

.38

.50.22

.38

.50

Hits

.33

.80

.50

.33

.50

.71

.67

.25.88

.36

.62

FK

Misses

.67

.20

.50

.67

.50

.29

.33

.75.12

.64

.38

Note.—Ms are: FK Hits, .76, Misses, .24; FK Hits , .57, Mis8es,.43.

probability for four equally likely

multiple-choice answers.

The departure of the FK miss

proportion from the expected .25 led

the investigator to look for possible

artifacts. A perusal of the multiple-

choice questions suggested one possi-

bility immediately. Many of the

multiple-choice alternatives did not

seem equally likely, that is, a person

ignorant of the correct answer but

possessing some related knowledge of

the field covered by the question might

be able to narrow the alternatives downto three or two, thereby raising his

guessing probability to .33 or .50. For

example, in the sample question about

the author of The Tempest, many sub-

jects might be able to narrow their

guesses to the English writers, Jonson

and Shakespeare.

EXPERIMENT II

Method

To correct for this possible artifact, 25additional questions were carefully con-structed to be used in a replication experi-ment. An effort was made to make the al-ternatives appear equally likely to theuninformed subject. Additionally, it wasdecided to see if subjects oould make graded

rather than dichotomous judgments abouttheir feelings of knowing. This was done tosee if the FOK experience operates as asimple Yes-No indicator of memory storageor if it operates at various graded strengthsfrom definitely Yes down to definitely No.Aside from these two changes, the materialsand procedure for Experiment II wereidentical to those of Experiment I.

Materials

The subjects in Experiment II were given75 general information questions—the 50received by the Experiment I subjects, plusth e 25 harder questions. A few sample

questions are listed below:Who painted "Afternoon atLa Grand Jatte"?

a. Monet b. Seurat c. Cezanned. Dufy

What sea does West Pakistan border?a. Arabian Sea b . Caspian Sea c. Red Sea

d. Black SeaWho developed the nonsense syllable

in studies of learning?a. Ebbinghaus b. Hull c. Pavlov

d. Wundt

Procedure

The 16 subjects in Experiment II weredrawn from the same subject pool as thosein Experiment I. They received the Bamegeneral instructions and listed their answersto th e recall and recognition tests on similaranswer forms. Only this time they wereasked not merely to check in either the Yes

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212 J. T. HABT

TABLE 3

RECALL AND RECOGNITION SCORES

EXPERIMENT II

Tests

Recall

CorrectIncorrect

ErrorsBlanks

FK

FK

Recognition

CorrectIncorrect

it

29.745.34.8

40.515.425.1

51.623.4

SD

7.57.5

2.98.2

4.9

6.7

5.45.4

Note.—Seventy-five-item tests, N = 16.

or No columns next to the unanswered ques-tions but to enter a rating of their feelingof knowing or not knowing. The rating wasmade with the following scale (the scale wasdrawn on a blackboard in front of thegroup):

Feeling-of-Knowing Rating

Yes No

Verystrongly

Verystrongly

Special instructions were added to explainthe use of this scale:

"You will notice that next to the answerbox for every question there are two col-

umns. On every question that you cannotanswer you should make a rating in eitherthe Yes column or the No column. This isthe way the ratings should be assigned

[illustrate on the blackboard]."If you cannot answer the question but

feel that you know it, place a 4, 5, or 6 inthe Yes column adjacent to the unansweredquestion. If you cannot answer the questionand feel that you do not know the correctanswer, place a 3, 2, or 1 in the No column.A 6 in the Yes column means that you feelvery strongly that you know the correctanswer even though you can't remember itat the moment. If you place a 1 in the Nocolumn, that means you feel very strongly

that you don't know the correct answer. Theintermediate ratings should be used for lessdefinite feelings of knowing or not know-ing."

The criterion question that subjects wereto ask themselves before making a ratingwas explained in the same words used withthe subjects in the first experiment.

Results

Table 3 contains a breakdown of therecall and recognition responses for

the 75-item tests. The data were first

analyzed by treating the FOK ratings

about unanswered items as dichoto-

mous Yes or No judgments to cor-

respond to those in Experiment I.

Table 4 shows that the overall test

of the accuracy of the FOK judgments

(FK hits compared to FK misses)

confirms the previous findings. For

TABLE 4

FK AND FK PROPORTIONS DIVIDED INTO HITS AND MISSES

EXPERIMENT II

5s

12

34

5

6

7

8

FK

Hita

.83

.61

.71

.69

.62

.67

.28

.67

Misses

.17

.39

.29

.31

.38

.33

.72

.33

Hits

.56

.60

.53

.63

.63

.53

.81

.70

FK

Hisses

.44

.40

.47

.37

.37

.47

.19

.30

•* >

910

11

12

13

14

15

16

FK

Hits

.68

.83

.59

.75

.56

.69

.62

.70

Misses

.32

.17

.41

.25

.44

.31

.38

.30

Hits

.55

.68

.62

.67

.56

.71

.55

.66

FK

Misses

.45

.32

.38

.33

.44

.29

.45

.34

Note.—MB are: FK Hits, .66, Misses, .34; FK Hits, .62, Misses, .38.

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MEMOBY AND THE FEELING-OF-KNOWING 213

every subject, more FK items aresubsequently recognized than FKitems (p < .001, one tailed ).

The breakdown of the FK and FKitems into hits and misses shows inTable 4 that, as before, the FK indica-tor is an accurate indicator of memorystorage. This time, however, the FKindicator is shown to be an equallyaccurate indicator of what is not instorage. Indeed, in Table 4 there areno reversals from the predicted direc-

tion of hits over misses. This significantresult in Experiment H a n d the ab-sence of a significant FK result inExperiment I can be attributed to theinclusion of harder questions in Ex-periment II, questions that would givethe subjects more definite feelings ofnot knowing when they were unable tocome up with an answer, and to theinclusion of multiple choices on therecognition test that would seemequally likely to an uninformed sub-ject. Yet even though the FK resultis significant, it is clear that the ob-tained proportion of FK misses de-parts from what would be expected ifthe subjects were simply guessing.

Perhaps_ th is departu re from th eexpected FK proportion can be expli-

cated by looking at the data in termsof the ratings rather than the Yes-Nodichotomization. Table 5 shows abreakdown of the data across ratingsfor the proportion of items correct ineach rating category from 1 to 6. Inthe terminology used earlier, 1, 2, and3 would correspond to FK misses and4,5, and 6 to FK hits.

Two proportions are given undereach rating category; the first wasobtained by summing across the pro-portions for subjects and then calcu-lating the mean of the summed pro-portions, the second by summing theitems correct in each category acrosssubjects and then dividing by the total

TABLE 5

PROPORTIONS FOB ITEMS CORRECT SUB-

DIVIDED AcCOBDING TO FOK

RATINGS

MethodRatings

Meansof summed pro-

po rtio ns .30 .53 .48 .54 .57 .78

Propor t ionsof summed

scores .30 .53 .50 .60 .61 .75

Note.—Two-tailed z tests show that allthe proportio ns are significantly differentfrom the chance level (.25), p < .005, ex-cept the values under Rating 1 (.30), forwhich p > .05.

number of items in that category toobtain a proportion. The second set ofproportions probably come closer to

the true values that would have beenobtained if m any more items had beenincluded, say 200-300 instead of 75.The mean proportions are likely to beunstable because, for the middle cate-gories, some of the cell entries forindividual subjects were very small;the procedure of taking the mean ofthe proportions weights each cellequally, consequently an entry for one

subject based upon only one item isweighted just as heavily as an entryfor another subject based upon 10items.

Descriptively, the mean propor-tions seem to be graded into three stepsfrom 6 (definitely Yes) to 5, 4, 3, 2,(maybe) to 1 (definitely No); whilethe summed proportions appear to be

graded into four steps from 6 (defi-nitely Yes) to 5 and 4 (maybe Yes) to3 and 2 (maybe No) to 1 (definitelyNo). Neither of these descriptivetrends are statistically validated, how-ever, since the data are too variableand the cell entries are too small.Only the proportions under Rating 1

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214 J. T. HABT

and R atin g 6 are significantly differ-ent. A t test for correlated scoresyields t = 3.38, p < .01 for the mean

difference .30-78. All the other differ-ences could occur with a p > .05.Consequently, these descriptive trendsare mentioned only as possibilities tolook for in la ter research.

What is clear from the rating-scaledata is that when subjects feel defi-nitely that they do not know an an-swer, they score on those items at

about the chance recognition level;when they feel definitely that they doknow the answer, their scores are th reetimes th e chance level.

DISCUSSION

The results of Experiments I and IIcertainly indicate th at FO K judgmentscan be used as relatively accurate

indicators of what is and is not inmemory. Earlier, in the introduction,the claim was made that the mostimportant and interesting question toask about FOK experiences is: "Arethey accurate?" Now that the resultshave given a "yes" answer to thisquestion, it is pertinent to look at thequestion again and ask: "Why is it

important that FOK experiences beaccurate? And, if they are, so what?"Is the FOK phenomenon anythingmore than a curious and common sub-jective experience? Does the experiencehave any usefulness in daily life?

Beginning answers can be made tothese questions by recognizing thathuman beings function cognitively

as information-processing system s, sys-tems with enormously flexible butfallible storage and retrieval capa-bilities. It is this fact of memoryfallibility that makes FOK experiencesimportant. If human beings werecomputers with infallible memories sothat they could always immediately

retrieve memory contents, then theywould not need FOKs. A memoryitem, if in storage, would be retrieved;

failure to retrieve an item would meanthat it was not in storage.

Clearly, however, human beings donot operate this way—retention oftenexceeds recall. Th e repeatedly observeddiscrepancy between common meas-ures of retention (recall, reconstruc-tion, recognition, and savings) showsthat there is not a simple one-to-one

relationship between storage and recallin the human memory system. Thephenomenon of reminiscence is anotherexample showing that what is im-mediately retrieved may not be anadequate indicator of what is re-tained.8

For a fallible memory system, asystem in which what is retrieved doesnot completely mirror what is stored,the FOK experience can serve a use-ful function. It can serve as an indi-cator of what is stored in memorywhen the retrieval of a memory itemis temporarily unsuccessful or inter-rup ted. If t he indicator signals tha t anitem is not in storage, then th e systemwill not continue to expend uselesseffort and time at retrieval; instead,

input can be sought that will put theitem into storage. Or, if the indicatorsignals tha t an item is in storage, thenthe system will avoid redundantlyinputting information that is already

But to be useful a FOK indicatormust be accurate. The determination

of the accuracy of FOK-derived FKand FK judgments is basic to an

1Any of the standard sources on human

learning, for example McGeoch and Irion(1952) and Hovland (1951), contain dis-cussions, data, and references about com-parisons between different measures ofretention and about the phenomenon ofreminiscence.

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MEMOHY AND THE FEELINQ-OF-KNOWING 216

evaluation of the utility of FOKexperiences because an inaccu rate FO Kindicator would add nothing to the

efficiency of th e fallible human m emorysystem. Indeed, the operation of aninaccurate indicator would increasethe system's fallibility and produceextremes of inefficiency. With aninaccurate indicator a person wouldpersist in trying to remember what hehad never learned or had forgotten,and he would not persist in efforts to

remember information that, with per-haps only a few more tries or a rest ora new kind of retrieval search, wouldeventually be remembered.

The important finding of the in-vestigations reported is that FOKexperiences are relatively accurateindicators of memory storage. Sub-jects can, by referring to their FOK

experiences, make accurate judgmentsabout which items they will be able toremember and which they will not.Of course, their predictions are notperfect and there are individual differ-ences among subjects in accuracy, buteven so the FOK phenomenon seemspowerful and reliable.

Since the FOK experience or phe-

nomenon refers essentially to the FKor Yes state of the indicator, it mightbe better to introduce a more generalterm to describe the overall processwhereby FK and FK judgments aremade about unretrieved mem ory items.Hereafter, the phrase "memory-moni-toring process" will be used to refer tothe intervening process producing FK

and FK judgments. Operationally,within the RJR paradigm described,memory-monitoring accuracy is meas-ured by counting how well subjectspredict which answers they will and

ill not recognize after they have beenbl to answer th e questions by

recall.

Although the memory-monitoringprocess has been introduced and de-fined with reference to the E J R

paradigm, it is clear that other para-digms might be applied to opera-tionally bracket this phenomenon.For example, after subjects have madeFOK judgments about items theycannot retrieve, they could be askedto continue efforts to recall the unre-trieved items—more FK items shouldeventually be retrieved than F K item s;

or, if cues are introduced one at atime about sought-after items, fewercues should be required for the identifi-cation of FK than FK items.

The phrase memory monitoringwas chosen to describe the processintervening between recall and recogni-tion because it seems descriptivelymeaningful yet theoretically neutral.

When subjects make FK and FKjudgments, they, in some way, monitoror check what they do remember toarrive at a decision about what theymight, remember. Memory monitoringrefers only to the intervening process,the process which leads to FK andFK responses whose accuracy can beobjectively evaluated within the EJR

paradigm. How the monitor works,the neural mechanisms necessary toaccomplish memory monitoring, thevariables that affect monitoring ac-curacy—these are unknowns.

But even with so many unknowns,it is clear that questions about FOKexperiences are not silly questions.The memory-monitoring process ap-

pears to be an important process,contributing significantly to the effi-ciency of the human information-proc-essing system.

REFERENCES

HOVLAND, C. I. Human learning and reten-tion. In S. S. Stevens (Ed.), Handbook of

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216 J. T. H A B T

experimental psychology. New Y o r k : SIEGEL, S. Nonparametric statistics. NewW iley, 1951. P p. 613-687. Y or k: M cGr aw-H ill , 1956.

JAMES, W. The principles of psychology. WOODWORTH, R. S., & SCHLOSBERG, H. Ex-

Hew York: Dover, 1950. perimental psychology. (Rev. ed.) New

M CGEOCH, J. A.,& IRION, A. I. The psy- York: Holt, 1964.chology of human learning. (2nd ed.) NewY or k: Lon gm ans, Gree n, 1952. (Received M arch 23, 1965)