The Industrial Worker: Volume I The Industrial Worker: A Statistical Study of Human Relations in a Group of Manual Workers, Volume I [Reprint 2014 ed.] 9780674369214, 9780674369207

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THE INDUSTRIAL WORKER VOLUME I

LONDON : HUMPHREY MILFORD OXFORD UNIVERSITY PRESS

THE INDUSTRIAL WORKER A STATISTICAL STUDY OF HUMAN RELATIONS IN A GROUP OF MANUAL WORKERS

BY

Τ . N. W H I T E H E A D Associate Professor, Harvard Graduate School of Business Late Scientific Officer to the British

Administration

Admiralty

VOLUME I

H A R V A R D U N I V E R S I T Y PRESS CAMBRIDGE,

MASSACHUSETTS 1938

COPYRIGHT,

1938

B Y T H E PRESIDENT AND FELLOWS OF HARVARD COLLEGE

PRINTED AT T H E HARVARD UNIVERSITY PRESS CAMBRIDGE, MASS., U . S . A .

To J[4y MARGARET

Wife WHITEHEAD

FOREWORD who are interested in questions of labor and working conditions in industry associate North Whitehead's name with another book he has written entitled Leadership in a Free Society. In this other book he described certain experimental inquiries in industry, but his attention, for the most part, was given to the wider implications of modern industrial and social change. In the present volume he gives the other side of the story. He is here concerned with detailed observation made upon a few women workers at a bench — the changes that· occurred during several years, some experimental, others by inadvertence — the effect of such changes. All this he describes with great precision. Logically this book may be considered to precede his other; actually it is more easily read, and more clearly comprehended, as a sequel. THOSE

The work presented is probably unique in at least two respects. In the first place it represents twelve years of work, six years of continuous and carefully contrived observation, six years of recalculation and analysis. But a second respect is equally worthy of notice; while the experimental room was devised and maintained by the officers of the Western Electric Company at Hawthorne, the analytic work has been done by North Whitehead and his assistants in the Graduate School of Business Administration at Harvard. Collaboration of this order between a large business and a university is not unknown, but it is not by any means sufficiently usual as yet. It is very unusual indeed in matters of inquiry into problems of human association and effort; the best business and university collaboration of the present has been given to technical and economic problems. Since the war there has been an important increase of interest in the problems of labor — the real problems of the working bench and the working group and not the abstract problems of the classroom and the textbook. In consequence of this there has been much observation of actual working conditions, and some experiment. The tradition of the war has held, however, in that it is rare to find in the records any sufficient length of time given to experimental determination. The effect of rest periods, of shorter work periods, of intervals for food and refreshment — many such questions have been determined by experimental changes of a few weeks or months. But there are probably few instances of inquiries that have been carried on for three or four years after satisfactory results have been achieved — that is, results satisfactory both to management and to the workers themselves. If the "test room" had been shut down after one year of experiment, the conclusions would not have differed in any important respect from conclusions arrived at independently and elsewhere. It was the prolongation of the inquiry to an approximate

FOREWORD

viii

six years that made possible the analytic work which Whitehead here presents. And it is upon the sufficient basis of a very great number of observations made in six years of continuous inquiry that this distinctly novel contribution to the understanding of working conditions is founded. A special interest, however, is centered in North Whitehead's own work. The essential simplicity of the method he has used, the evident quality of his conclusions — this intelligibility serves to conceal from the casual reader the long and careful effort required to put order into the mass of data supplied. Certain of the original measurements had to be slowly and laboriously remeasured; extensive calculation was a necessary preliminary to the considered contrivance of a technique of presentation. The presentation of facts invariably implies something of selection; before this selection could be made Whitehead had to work carefully through all those observations other than measurement made by the Western Electric officers who conducted the experiment. This led to consultations with these officers and in certain instances to discussion with the workers themselves. From all this work, faithfully done and admirably elaborated, have emerged the discoveries published in this book. It must not be supposed, however, that the observations offered here by any means exhaust the material. The selection from a mass of certain items that, in popular phrase, hang together and consequently offer themselves for elaboration — any such selection tends to indicate to the expert worker certain other groups of data which equally demand attention. In this North Whitehead's work does not differ from that of another scientific investigator. He is already at work upon a volume of observations that will supplement this, and will further enhance its value. One cannot end this foreword without acknowledgment of the many and various contributions that have made the work possible. The contributors are of two kinds: those who actually did the work and those others who by their moral and financial support held it in being for twelve years. In the first class special mention must be made of those officers of the Western Electric Company whose intelligent insight designed and adapted the experiment, whose courage and persistence carried it through. In the second class, also, the Western Electric Company stands high, as do the Rockefeller Foundation and Harvard University. ELTON MAYO MAY

20, 1937

PREFACE THIS BOOK presents an analysis of an industrial group consisting of a few young women, who were continuously engaged in the repetitive assembly of small electrical relays for a period of about five years. The analysis is based on exceptionally complete records and on a first-hand acquaintance with the experiment and with the members of the firm who were conducting it. The analysis relating to the Relay Test Group has been proceeding along two main lines. On the one hand, it throws light on the nature of individual skill in such an occupation; its acquisition, and its maintenance. Skill of this sort is found to be closely connected with the growth of discrimination, and the evolution of rather flexible patterns of operation, and also with the direction given to attention by the attitudes of the group towards their work situation. Investigation on these lines is proceeding, and it is intended to present the results in a later publication. The present book is concerned with another aspect of the work. Both the numerical and the contemporary descriptive records provide material for an analysis of this working group regarded as a social system. It has been found possible to relate the common activities, the social sentiments, the thoughts and the conceptual schemes of these workers, and so to obtain some understanding of their motives and satisfactions in work as a part of this social process. T h e Relay Test Group was a small society in which the logical purpose and the immediate satisfactions of its common activity are examined in their relations to one another. This study is complete in itself, although it is closely connected with the alternative study of individual skills. From another point of view, this book may be regarded as a companion volume to a work by F. J. Roethlisberger and W. J. Dickson. 1 These authors describe a research, or perhaps one should say a series of co-ordinated researches, undertaken by the Western Electric Company at its Hawthorne Branch, Chicago. T h e authors' account is both historical and critical; historical, in that the researches are described chronologically, and the authors show the evolution of ideas by which the project was guided; critical, in that the findings are discussed and certain hypotheses are advanced. T h e longest single research described in "Western Electric Researches" is that of the Relay Test Group. It was also the first of the series undertaken by the Western Electric Company, and in some respects it was the most elaborately organized and most carefully watched. However, in a general account of a group of researches it would not have been pertinent to analyze any one of them in great detail. 1 Shortly to be published by the H a r v a r d University Press. Inasmuch as this book has not yet received its final title, it will be referred to as "Western Electric Researches."

χ

PREFACE

At the same time, the records of the Relay Test Group merit an independent analysis; they probably represent an almost unique body of material, having regard to the length of time during which the experiment was conducted, the immense quantity of numerical data collected, and the support that these receive from more obviously psychological and sociological material, simultaneously recorded. This book is divided into five parts. Part I briefly describes the setting of the experiment, the group of workers, and the available records. It also discusses certain problems connected with the use of these last. Part II investigates the effect on work behavior of certain changes in the material environment of the workers. The direct relation between these two sets of variables is found to be slight, over the range explored. Part III gives an historical description of the daily life of the workers, in so far as this is known, together with a sketch of their interests and their preoccupations. Attention is drawn to the relations existing between the various members of the group. In Part IV an analysis of the numerical records of output reveals the unexpected degree to which the workers were influencing one another in their work behavior. Moreover, the ways in which these girls influenced one another are found to conform to their social relations as described in Part III. In Part V the findings from the previous parts are summarized and discussed. In at least one respect, the researches conducted by the Western Electric Company represent the development of a new attitude on the part of industrialists towards their human problems. Executives in progressive firms are usually concerned with their workers, and alternative arrangements are continually being tried out in an endeavor to provide men and women with suitable working conditions. Research of this kind can be compared to the pioneer work of engineers in the first half of the last century. They were experimenting with the various materials of construction, and particularly with iron and steels. The method was to try the material out by using it in a variety of shapes and sizes for a number of practical purposes. Sometimes the metal stood up to its duty and at other times it did not. The latter arrangements were discontinued, and so the engineer proceeded step by step to a knowledge of the suitable uses of his material. This kind of practical experimentation has proved to be indispensable and every engineer uses it today, but he has added another experimental technique to his stock in trade. Besides trying out a material in practical situations, he submits it to a series of logically connected tests which have no immediate correspondence with practical conditions; he analyzes his material chemically, he tests its resistance to corrosion when placed in various known substances, he tests its resistance to mechanical stresses of several sorts, he tests its liability to fatigue under repeating stresses, he tests its behavior under varying temperature, and he tests it in a number of other ways. These tests are so devised as to give some understanding of the laws governing the behavior of the material over a wide range of definable conditions, and by the help of these laws the engineer can

PREFACE

χι

so use his material as to obtain the maximum of advantage in a given practical situation. A logical understanding of the characteristics of a material has proved to be an indispensable framework for the best development of practice. Until fairly recently, the activity of human beings has not been investigated in any logically coherent manner, but the last half-century has seen the rise of an experimental psychology which has attempted to achieve this very thing. On the whole, the results have been a little disappointing. People are far more sensitive than are materials of construction to their wider environment, and the relation between a man and his environment is extremely complex. In consequence, experiments performed on a man in a psychological laboratory do not always throw much light on the same man's behavior in daily life. This difficulty has delayed the effective investigation of the laws governing the thought and action of human beings. Evidently, men and women must be examined under conditions which are sufficiently typical of their daily experience, and yet which permit of an orderly investigation, not restricted by the necessity of finding an immediate solution to a practical problem. T o the development of this type of fundamental experimentation, the Western Electric Company has made a major contribution. Starting with the notion that management should know more about its human material, in the sense that they know about their materials of construction, the responsible executives started a research which gradually departed from the notion of trying out alternative practical arrangements and they developed techniques for obtaining a logically coherent understanding of the employee as an individual and as a member of a working team. The Western Electric researches have obtained results of immediate practical importance, and they have also led to some preliminary glimpses of the laws governing human behavior. A t any rate, they have directed attention to fruitful questions and have suggested methods for seeking the answers. It is, perhaps, not too much to hope that this company has laid the foundations for orderly research into the motives and activities of men and women employed in industry. A few members of the Faculty of the Harvard School of Business Administration, led by Professor Elton Mayo, have been continuously interested in the Western Electric researches since their inception, and much of their work has been connected with the observation and consideration of these researches. The present book is a direct outcome of this work and, although I am responsible for the actual analysis in the form in which it is presented here, this is the result of a continuous collaboration with my colleagues, and many of the ideas have been developed in common between us or as an immediate result of Professor Mayo's teaching and leadership. The calculations involved in the present work have been exceedingly laborious, even more so than appears from the outcome, for many statistical devices or calculations were tried which failed to produce results, and these have not been reported. I am indebted to all those who at one time or another have been engaged in this

Xll

PREFACE

task of computation; and I am particularly indebted to Miss Helen M. Mitchell and Miss Grace Laing who have been continuously engaged in this work since it began. Miss Mitchell has been in charge of all calculations throughout, and she has been largely responsible for devising suitable calculation forms which have proved convenient both for the original computations and for their subsequent checking. It is due to Miss Mitchell's skill in these respects that there have been so few opportunities for the inevitable errors of calculation to pass undetected. It is perhaps too much to hope that no errors of calculation have escaped our notice, but the checking has been so thoroughly performed that these should at least be very rare. But for the skilled and painstaking work of Miss Mitchell and Miss Laing these calculations could not have been performed. I am further indebted to Miss Mitchell for having prepared and drawn every one of the diagrams in this book. Good diagrams are of vital importance as a pictorial presentation of statistical facts which can hardly be conveyed to the reader in any other way, and the first requisite of a diagram is that it shall present its facts as clearly and convincingly as possible without distortion. I am fortunate in having had the help of so skilful a draftsman to present my facts for me. Finally, my thanks are due to Mrs. Τ. H . Thomas for editing the manuscript and revising the proofs, and to my Wife for providing the Index.

CONTENTS Foreword by Elton Mayo

vii

Preface

ix VOLUME I PART I —

INTRODUCTION

CHAPTER

ι

Scope and Method of the Analysis

2

The Setting of the Experiment

3 13

PART I I — T H E MATERIAL ENVIRONMENT

3

The Scope of Part II

31

4

Output and Its Representation

33

5

The Experimental Periods

38

6

Hours of Rest

45

7

Periodic Illness

51

8

Cyclical Changes, Vacations, and Holidays

55

9

Changing Types of Relays

62

10

Temperature and Relative Humidity

75

11

Records Concerning Quality

86

12

Variety as an Ingredient in a Total Situation

88

P A R T I I I — T H E SOCIAL PROCESS —

DESCRIPTIVE

13

The Scope of Part III

97

14

The Problem and the Experiment

99

15

The Establishment of Routines and Sentiments

16

Organization of Social Activity in Subordination to the Experiment .

17

Transitional Phase —1930

152

18

Organization of Social Activity for Its O w n Sake

164

19 The Novices

108

. PART I V — T H E

20

Scope of Part IV

21

Time Spans

.

120

186 SOCIAL PROCESS —

ANALYTIC

22 Pair Relationships in the 1 Day—1 Week Time Span

191 192 203

xiv 23

CONTENTS Total Pair Relationships in Three Time Spans

24 Pair Relationships in Short Time Spans 25 The Persistence of Attitudes

219

.

26 The Forming of New Attitudes.

209 220

.

229

P A R T V — CONCLUSION

27 The Organization of the Relay Test Group

239

1. The Significance of the Experiment.

239

2. The Nature of Social Adjustment

239

3. Evidence of the Statistically Determined R e l a t i o n s h i p s . . . .

243

4. The Development of a Social Attitude 5. The Maintenance and Modification of a Social Attitude .

248 . 251

6. The Connection between Attitude and Activity

253

7. The Relay Test Group as a Social System

253

8. Three Characteristics of a Social Process

. 255

Appendix. Notes from the Chicago Tribune Relating to Spells of Exceptionally Hot or Cold Weather 1927-1932 259 Index for Volumes I and II

.

263

PART I INTRODUCTION

CHAPTER

1

SCOPE AND M E T H O D OF THE ANALYSIS

describes an analysis of extensive data referring to one small group of individuals. Before proceeding to this task it will be worth while to consider the possible scope of such an undertaking, and the methods which have been used. T H I S BOOK

The Use of Small Samples The sizes of the statistical populations we shall be considering vary greatly. At one end of the scale are the hundreds of thousands of relays assembled by each girl during the course of five years. Then there are intermediate populations of one sort or another varying from several hundred to a few dozen. But above all, there are at any given time five relay assemblers and one small wording group·, for these are the two entities with which this research is really concerned. So, although we may be incidentally operating with large numbers, our real task lies with a small sample of five, or with a still smaller sample of one. A doubt is often expressed as to whether much statistical research is warranted on so narrow a basis. This is a vital question, and not only in the present instance, for it is observable that much research is deliberately concerned with very small samples, even when larger samples are readily available. Small samples of large populations are frequently used in the biological and social sciences; and a considerable mathematical literature is springing up to adapt the mathematics of probability to this particular end. But in the case of most of the mathematics and in a large proportion of the investigations, it is assumed that a sample acquires virtue in some proportion to its size. The best sample of a whole population, on this understanding, would consist of all the members. Since practical considerations usually forbid this, the sample is chosen to be as large as possible, and a small sample represents the unfortunate case where it has not been possible to make a really adequate investigation. The statistical limitations of small samples are too well known to be detailed here; they broadly fall under two heads. A small sample yields little knowledge of the distribution of any characteristic amongst the members of the larger population. Secondly, no application of the principle of indifference will make it reasonably certain that a small sample contains representative members from the larger population. Both these statements amount to saying that a knowledge of a population cannot be gained by a mere formal manipulation, of the facts obtained from a small sample. In this respect, a small sample is less fitted to yield information than a larger

4

THE INDUSTRIAL WORKER

sample. But this does not exhaust the subject, for a moment's thought will show that on many occasions small samples are deliberately chosen in preference to larger ones in every branch of science. Suppose, for instance, that we wish to understand the basic functioning of steam engines; would it be wise to investigate the detailed information relating to a thousand steam engines? Such information is readily available, but this is not the way in which the engineering student is trained. On the contrary, one particular steam engine is chosen for detailed study, and within limits it does not matter which. From this study the student gains some insight into the behavior of water at various temperatures and pressures, and also a knowledge of the types of structures which convert the steam pressure into rotary motion; he learns the structure and function of the boiler, cylinders, pistons, the valve gears, and so on. These structures, in their most general form, are common to the whole population of reciprocating steam engines, and when the student has mastered one he is, in a general way, in a position to understand every engine within the population. He has the insight or understanding which enables him to systematize his scattered observations of any other steam engine he may subsequently examine. Put briefly, a population with important elements of homogeneity can be studied in two different ways. First, any one member can be examined and studied closely to obtain insight into its structures and its modes of functioning. This, in virtue of the homogeneity of the population, gives a basis of understanding to the observed behavior of any other member. Secondly, a large sample of the population may be studied to obtain information as to the type, degree, and distribution of variety within the population. All human beings have certain general characteristics in common, but only the analysis of large samples will tell us how these characteristics vary in degree as between individuals. This statement opens up a number of problems. In what way, and to what degree, does a knowledge of one individual — its structures and their functions — lead to a knowledge of other members of the same population? To say that the population is homogeneous really begs the question, for no two members of a homogeneous population are quite alike in any single respect. More than that, it may well be that no character relevant to the investigation is found even amongst the members of the homogeneous population sufficiently alike in quantity to be thought of as uniformly distributed over the population. This is particularly true where the members are living organisms. The mathematical tests of homogeneity indicate how far a population will prove amenable to a given mathematical technique; but it is for the investigator to decide what variations of character within a population are compatible with a unity which is meaningful to him. This consideration is essentially one of judgment, for which mathematical procedures cannot be substituted, although these may well be part

SCOPE AND METHOD OF THE ANALYSIS

5

of the evidence on which the judgment is based. Thus, a population of members might be put together consisting of all animals from frogs to human beings, and, with respect to some character such as acquisitiveness, the population could perhaps be so selected as to have a normal distribution. But this would not necessarily be a significantly homogeneous population. To be significantly homogeneous, the similarity between the members of a population must be such that any understanding of the functioning of one member in terms of the given characters would lead to a significant insight into the functioning of the other members in terms of those same characters. Any given character need not be, and never is, present to quite the same extent in the various members of a population. A population is significantly homogeneous when a range of characters important to the understanding of one member is also important to the understanding of the other members, and in much the same way. If it were not for this expectation, the study of individuals or samples (large or small) would provide no basis for any understanding of total populations. Moreover, in the case of small samples this expectation cannot arise solely from a consideration of the sample itself. A prior belief as to the relevance of the small sample to its population must be entertained. The small sample, including under this head the single member, gives virtually no mathematical information as to the homogeneity of its population. The single member is, however, the ideal size for gaining insight into the functioning of the individual members, provided it can be presupposed that the insights gained from any one member are substantially relevant to any other member. If we have a population about which we know nothing, no study of one member can give any insight as to the characteristics of the remaining members. But a population which is sufficiently recognized to be the subject of an investigation is, by hypothesis, not completely unknown. The usual case is that the investigator has a large, but often unsystematic, knowledge of the population, and any systematic understanding of one member gives logical coherence to the observed behavior of the other members. In so far as the structures and functions of one member do, in fact, illuminate or "make sense of" the behavior of the other members, to that extent is the homogeneity of the population confirmed for those characters. It will be noticed that homogeneity is not an "all or none" property of a population; on the contrary, it has both degrees and modes. A single member is the ideal sample by which to examine an organism or a mechanism whose various processes are logically related in time. Thus, if we examine the behavior of a child during a day, it will be found to be doing a number of different things; and the order in which these things happen is important to the understanding of the child as a functioning organism. Thus, if we notice that the child first learns a lesson and then applies it to some problem, we have observed a sequence of events which has significance for us, which we partially understand,

6

THE INDUSTRIAL WORKER

and which we can perhaps understand further by a detailed consideration of the particular instance. If these two events are considered without respect to order, or in their reverse order, the whole functional significance is lost. The study of the single member has an historical aspect, in that, almost necessarily, behavior is observed in the order in which it occurs. The various events observed do not obtain their importance from their similarity, for they are apt to be very different, but rather from their functional coherence; they are subject to causality or to the relation of mutual dependence. Thus, if an animal in a maze is found to avoid those passages which result in an electric shock, the reception of the shock and the subsequent avoidance of the passage are two very different kinds of events; and their combined importance results from the time order in which they occurred and the single organism to which they refer. The animal avoided the passage "because" it had received a shock. The word "because" indicates the logical nexus and also the significant aspect of the experiment. Now, as a contrast, consider the techniques available for investigating large samples. These techniques are almost entirely mathematical. In the simplest case, the numerical values of some one character are ascertained for all the members of the group. The information derived from this group of statistics may be the mean value of that character for the members, the law expressing the relative frequency of each numerical quantity within the sample, and so forth. Here, the occasions or events considered are all similar as regards quality, and the variation is one of individual quantity. The various events have no functional relation to each other. My height is not functionally related to your height, although the functions relevant to each are very similar in kind. The events are not related in time; the time relation, if not fortuitous, is quite indirect, and is often not even recorded. Comparing methods appropriate to small and big samples, we can characterize them as follows: A method is appropriate to a small sample when each member is studied as an enduring organization and its events are examined in their natural time sequence, and in their functional relationships. These events are of different qualities and they obtain their collective significance from the nature of their functional relations. A method is appropriate to a large sample when some one class of events (or at most a few classes) is ascertained for each member. The events in one class are all of the same character, and they derive their collective importance from the very fact that they are not tied together by functional relationships. Relations between some few classes of characters can be directly investigated in this manner, but not an enduring organic process in which the single events are essentially unlike but are functionally related. Let us now consider the manner in which small samples are chosen to be sufficiently representative of a population. Piaget conducted some famous experiments

SCOPE AND METHOD OF THE ANALYSIS

7

on the thought and language of two children between the ages of seven and eight years. Had these been very unusual children, he would, from his knowledge of children in general, have realized early in his investigation that such was the case. Most readers will conclude that these two children were in fact fairly average specimens. This illustration reminds us that the selection of a very small sample (one or a few members) is not usually accomplished by'chance'as, for instance, by drawing lots; the sample is usually deliberately selected as seeming typical of its population. And, even if the selection was haphazard in the first instance, by the time that the one or two members have been examined, the investigator bases his opinion of their representative character not so much on the techniques of selection as on his understanding of the population from which they came. Thus the techniques of selection do greatly affect the probability of representation in the case of large samples, but in the case of very small samples, reliance must be placed on selection based on the existing knowledge of the population, and in practice this is how small samples are actually chosen. The most significant advantage of a fairly numerous small sample lies in the possibility of combining to some extent the techniques applicable to both small and large samples and this practice is followed in the succeeding chapters. Thus, in analyzing the five Relay Test Room operators, the individuals are often considered separately, but on occasion their differences and similarities are also examined. For instance, their individual weekly outputs are taken together and result in a curve which represents the group output week by week. To what uses can this group output be put? In the first place, it will be noticed that the five operators, although working at different rates, show broadly similar increases of output during the course of the research; secondly, these individual increases occur at much the same dates. In other words, as regards changes in rate of output, all the operators are telling the same general story. So the first use of the group curve is simply as a shorthand way of referring to each and every operator simultaneously, with respect to those characteristics in which they are observably similar. The validity of this use of group statistics does not depend on the numerousness of the small sample. With much more reserve, a further use can be made of figures for group output. For we may observe that the differences in percentage increase of output as between operators over the whole period are not large as compared with the mean percentage increase as shown by the group figure. This leads to a presumption that, had any five operators been chosen indifferently from amongst a larger population of relay assemblers and given the same conditions as obtained in the Test Room, their output would have increased in a somewhat similar manner. Here the actual number of members in the small sample is decidedly relevant. If the percentage increase of output was very similar in all cases, five would be a reasonable number on which to base a moderate mathematical expectation. If, out of a large number of lumps of

8

THE INDUSTRIAL WORKER

an unknown substance, five were tested and found to float in water, this would lead to a strong belief that the specific density of the substance was less than that of water. Actually, the percentage increases in the outputs of the five members do not correspond very accurately; and this very materially weakens the expectation of a similar behavior on the part of the other members of the population. But we are able to transcend the knowledge available from internal evidence, owing to the fact that human beings, whether relay assemblers or others, are tolerably well known. From a study of the five members, taken as a small sample, we can deduce some of the reasons for the observed increase; also from a general knowledge of the population, it seems likely that the reasons which applied in the small sample would also apply generally. Hence we are left with a moderate belief that in the majority of cases had any five operators, indifferently chosen, been placed under similar conditions to those obtaining in the Test Room, their output would have increased in the same sort of way. This is an excellent illustration of the combined use of techniques applicable to small and large samples as applied to a fairly numerous small sample. The small sample investigation had supplied insight into the causes of the increase. The same sample, treated as though it were large, leads to a weak expectation that other individuals from the same population would behave similarly in similar circumstances. An unsystematic knowledge of human beings in general, and of relay assemblers in particular, strengthens this belief. Only further trials can determine the matter precisely and give limits to the probable similarity of this character as between any two members or groups; this would amount to an investigation of a very numerous sample based on the insights obtained from the original small sample. Other cases in which some approach to large sample technique is permissible when handling a fairly numerous small sample will be noticed in the body of the work. When this is done, it depends for its validity on the fact that a rather weak mathematical expectation is heightened by reference to a wide unsystematic knowledge of the larger population, a knowledge which cannot be so expressed as to form a part of the data on which the mathematical deduction is formed. Or there may be additional facts concerning the same sample which undoubtedly support a weak deduction, but which again cannot be mathematically related to it. Statistical Procedures Some of the statistical procedures used below are less refined than those commonly employed. This has partly resulted from the quantity of material to be handled and partly from another consideration. For there is no point in achieving a numerical precision greater than that required to substantiate the final understanding to which the calculation contributes, and it will be found that this research leads to some understanding as to the sort of way that people are likely to behave in certain sorts of circumstances. The final understandings are all qualitative, although

SCOPE AND METHOD OF THE ANALYSIS

9

they are based on numerical evidence, and the statistical work is, I believe, sufficiently precise to bear all the meaning which I have been able to discover for it. Similar considerations have led me to omit the calculation of a probable error (or its equivalent) where the significance of a result is beyond all reasonable doubt. The desire for precision, as distinct from absence of error, is an excellent characteristic of the modern scientist, but if overpressed, the result is barely distinguishable from pedantry. Although approximate methods have often been used, great pains have been taken not to fall into error either through faulty (as distinct from approximate) method, or through numerical miscalculation. All numerical calculations have been carefully cross-checked wherever possible, and have been repeated in other cases. Great reliance has been placed on diagrammatic rather than on tabular presentation of numerical results. The latter is no doubt a better procedure for those who wish to submit the results to additional manipulation. On the other hand, tables of numbers make an indigestible diet, little or nothing leaps to the mind from their casual inspection, and it is impossible to form an estimate as to the importance of tabular results without much additional work on the part of the reader. A diagram is an ideal presentation from which to obtain a shrewd estimate as to the order of importance of a series of facts. Sociological data rarely warrant a more close numerical record than can be given in a diagram. Some of the statistical devices used below have been devised to meet particular situations, but I am not sufficiently versed in the literature of statistical method to know whether they have any claim to novelty; in any case they are described in detail in the text or in the letterpress accompanying the figures. Only one device, which is well known to statisticians, need be mentioned here. Throughout this book, continual use is made of correlation. To give only one example, the rate of output for each operator is examined in relation to room temperature; this involves a calculation of the degree of correlation between these two variables (rate of output, temperature). In every case, the accepted definition of correlation has been used and, as the reader knows, such correlations are denoted by the letter r. Throughout this boo\, the degree of correspondence between two variables is always given as the square of its correlation, r", but the sign of the original correlation is retained. The square of a correlation is called a determination. Thus if the correlation, r, between two variables amounts to ±0.4 or ± 4 0 % , then the corresponding determination, r 2 , amounts to ± 0.16 or d= 1 6 % ; this latter is the figure invariably quoted. There are several reasons for using determinations rather than correlations. Some of these depend on the manner in which the judgment is affected, whilst others have reference to mathematical procedures which are thereby made possible. The following table will make the matter clearer. It gives the determinations corresponding to certain correlations.

10

THE INDUSTRIAL WORKER

It will be seen that the correlations and their corresponding determinations coincide at o % and at 100%, but that for all other cases the determination is numerically less than its corresponding correlation. For instance, when r = ± 50%, r 2 = ± 2 5 % ; thus the bottom half of the correlation scale is compressed into the bottom TABLE I Correlations, r

%

+

Determinations, r2

%

0

0

10

+

+ 20 + 30 +40 + 50 + 60 + 70 + 80 +90 + 100

I

+ 4 + 9 +16 +25 + 36 +49 +64 +81 +100

quarter of the determination scale, but the top half of the correlation scale occupies three-quarters of the determination scale. T h e following sketch illustrates this relation between the two scales. SKETCH

I

Scale Corresponding Scale ot of Determ 1 nations Correlations 100-

100

50 — — 50 O-

-o

THE INDUSTRIAL WORKER

II

The determination scale gives more space to strong relations between two variables and less space to weak relations, than the alternative scale. This is in accordance with common sense, for correlations of 30% and less are not usually of much real importance, however statistically significant. A correlation of 30% between two variables amounts to stating that the correspondence between them is not so very different from what would occur by chance, and it is misleading to find such a condition marked nearly one-third of the way up the scale; on the determination scale this correspondence would stand at only 9 % . There is no one right scale for relationship; the best scale is that one which most nearly illustrates the importance that the particular user attributes to the various states of relatedness; this importance varies for each individual and for every pair of variables. However, I think it would be true to say that, by the use of the correlation scale, investigators are habitually led to believe that a given degree of correlation is indicating a state of affairs much more important to them than it really is. Apart from more nearly reflecting the user's own sense of the importance of a relation, the determination possesses a useful technical advantage as compared with correlation. Suppose the degree of determination between two variables be found to be 36%, then the degree in which the relation is indeterminate is 100 — 36 = 64%. If this be restated in terms of correlations, we have a correlation of V0.36 X 100 = 60% and a failure to correlate amounting to V0.64 X 100 = 80%. But 60% + 80% = 140%, being the sum of the correlation + the relative freedom as between two variables in a given situation. A direct calculation of the degree of freedom between two variables whose r = 0.6 (r 2 = 0.36) would substantiate the above figures. Thus, expressed on the determination scale, and on this scale only, the degree of relation between two variables added to the degree in which they are not related sum up to 100% of the possible relationship. A convenient outcome of this is that the arithmetic mean and the product of two determinations have an importance which is denied to the correlation scale. To give just one instance, if variables A and Β determinate to an extent x, and variables Β and C determinate to an extent y, then the most probable degree of determination between A and C would be xy. This would not be true had the relation been expressed in terms of correlation. The determinations used below were obtained by calculating the correlations and squaring them whilst retaining the original sign. An example will show the manner in which measures of internal consistency (e.g. the p.e.) were obtained. Suppose a correlation to be found of 40% with a p.e. of ± 1 0 % , then the probable limits of relatedness as defined by the p.e. are 30% and 50%. Squaring all these figures, we arrive at a determination of 1 6 % with limits as defined by the p.e. of 9 % and 2 5 % . Thus the determination is 1 6 % p.e. — 7 % , + 9 % . The upper and lower ranges of the p.e. (or of any similar measure) are not equal on the scale of determinations. However, unless these ranges are large as com-

12

THE INDUSTRIAL WORKER

pared with the whole relation, the difference between them is trivial; in such cases the larger range is quoted as applying to both, e.g. above, r 2 = 1 6 % . p.e. ± 9 % . Although all figures quoted for this type of statistical relation are given as determinations, and never as correlations, yet some use has been made of the word correlation as referring in a general sense to a statistically determined relationship; no reference to a particular scale of measurement is ever intended when this word is used.

CHAPTER 2 THE

SETTING OF THE EXPERIMENT

manufactures equipment for the American Telephone and Telegraph Company. The former company operates a number of plants of which the largest, the Hawthorne Plant, is situated on the outskirts of Chicago, Illinois. The Hawthorne Plant has a capacity of about 40,000 employees, and it was fully manned prior to 1930, when the industrial depression began to make itself seriously felt in the manufacturing end of the telephone business. The policies and traditions of the Western Electric Company, in so far as these refer to problems of personnel, have been described in "Western Electric Researches"; 1 here it suffices to say that the Company enjoys a well-deserved reputation both for the policies themselves and for the manner in which they have been carried out. In a small firm, human relations depend mainly on the attitudes set by some few key men at or near the top. This is equally true in one sense of a plant employing thousands of men and women. But the means for controlling the relations of such large numbers must necessarily be more elaborate and formal. Accordingly, a whole network of subsidiary organizations, services, and customs have developed in the Hawthorne Plant, whose objects include the maintenance and improvement of human relations. One of the principal difficulties in regulating human relations in a plant of this size arises from the lack of immediate contact between its component groups, and particularly as between the shop employees and the responsible executives at the top. It is not easy for the latter to gauge the needs and sentiments of those lower down the scale. It was a recognition of this difficulty, on the part of the senior executives of the Hawthorne Plant, which led them, in 1927, to undertake a co-ordinated series of researches lasting over a number of years.2 These various researches grew out of one another and, though very different in their scale and in their techniques, they were all directed towards one central objective. This objective was described in the simplest way by one of the leading executives as a desire "to know more about our workers." The range of subjects on which information was sought was quite intentionally kept as wide as was compatible with orderly investigation; for it was felt that the research, to be effective, should not be limited to notions already present in the minds of those directing the work. Thus, it interested the management to know that many of their employees ate little or no breakfast before commencing their work and that these employees felt their work to 'drag' for T H E WESTERN ELECTRIC COMPANY

1 2

By F. J. Roethlisberger and W . J. Dickson. Described in detail, loc. cit.

i4

THE INDUSTRIAL WORKER

the last hour or so before the lunch interval. Again, the management wished to obtain a better insight into the workers' sentiments with respect to each other and to their supervisors. Anything was welcomed that would give a better understanding of the employee as a human being and as an industrial worker. The initial problem was to devise an appropriate experiment or research with which to make a start, for it was correctly supposed that once an effective beginning had been made, future research would develop out of the new problems and understandings resulting from the first. It was decided to begin by placing a f e w workers in a group by themselves with their own supervisor and to study them throughout a considerable period of time as they performed their habitual tasks. This group was placed in a small room, known as the 'Relay Test Room,' and it was studied continuously for a period of about five years. It is with this particular experiment that the present book is concerned. Other researches were started as soon as the Relay Test Group began to yield results, or at least to suggest new problems, and these later researches ran concurrently with the Test Room for a large part of the time. We shall confine our attention to the Relay Test Group; the subsequent researches have been extensively reported in the book already referred to. The Relay Test Group In April of 1927, five relay assemblers, young women, were taken from the main relay assembly shop and placed, together with the necessary service and supervisor, in a small workroom by themselves. Relations were established between these workers and management, of such a nature as would admit of a close and friendly observation of their behavior, their attitudes, and of other circumstances relating to them. In order not to complicate a study of employee attitudes and motives with problems relating to the initial acquisition of skill, the original Relay Test Group were all chosen from among those with considerable experience in the assembly of this kind of relay. T o distinguish these assemblers from others who subsequently came into the experiment, they will be termed experts, though they were not chosen for any unusual skill but merely for their experience in the work. So far as the responsible experimenters were concerned, the assemblers were chosen at random from the main shop, with one proviso: the girls were invited to volunteer for the service and no pressure was put on any individual to participate in the experiment against her own inclinations. However, the selection was not random in the sense that the names of volunteers were chosen by lot. The actual method of selection was quite informal and somewhat obscure; it appears to have been determined by the girls themselves in consultation with their shop foreman. Thus, of the eight assemblers who at one time or other saw considerable service in the Test Room, two pairs of friends came into the experiment together, another girl was a friend of a previous

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