On Measurement of Motor Skills: An Approach Through a Statistical Analysis of Archery Scores 9780231887489

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On M E A S U R E M E N T of MOTOR

SKILLS

n M E A S U R E M E N T of MOTOR SKILLS • An Approach through a Statistical Analysis of A r c h e r y Scores

By E L I N O R M A R I E

SCHROEDER

T

New York : Morningside Heights KING'S

CROWN 19 4 5

PRESS

Copyright 1945 by ELINOR M. SCHFOEDER Printed in the United States of America

King's Crown Press is a division of Columbia University Press organized for the purpose of making certain scholarly material available at minimum cost. Toward that end, the publishers have adopted every reasonable economy except such as would interfere with a legible format. The work is presented substantially as submitted by the author, without the usual editorial attention of Columbia University Press.

This is a war time book.

ACKNOWLEDGMENTS Generous help has b e e n given me in c o n n e c t i o n w i t h this study. I gratefully acknowledge the aid of the sponsors -Professor Helen M. Walker, P r o f e s s o r C l i f f o r d L. Brownell who was the original co-sponsor representing the Department of H e a l t h and Physical E d u c a t i o n until he entered military service, and Professor William L. Hughes w h o acted in his place

thereafter.

I am particularly indebted to P r o f e s s o r Walker for her very generous help in the p l a n n i n g and carrying out of the treatments and in the criticism of the work, and for many kindnesses that were not at all called for. I am grateful to her also for intellectual stimulus and for challenge.

In

its material form this study, whatever its values and weaknesses may be, very inadequately represents the personal and professional enrichment I have gained from the experience of working on it under the p r i n c i p a l adviser whose guidance

I was so fortunate as to receive.

I w i s h to express appreciation also to others who helped in various ways -- to Professor R u t h Elliott of Wellesley College

for encouragement and material aid, to those col-

leagues who advised me on c e r t a i n details, students who served as subjects

and to those

for that aspect of the

study which necessitated that scores be secured for a lesson of double

length. E. M. S.

CONTENTS

I.

INTRODUCTION:

THE NATURE OF ARCHERY

TO THE P R E S E N T

STUDY

.

.

AND GENERAL

.

APPROACH

.

The Nature of Archery and Common Conceptions Concerning Its Score.

.

.

.

.

.

1

6

Review of Literature. Purpose and Scope of the Present Study

10

Sources and Nature of Data

13

Statistical Treatment and Tests of Significance

IS

PART TREND II.

AND

RELIABILITY

GROUP L E A R N I N G

EACH

.

.

IN

OF THE

ONE SCORE

IN SUCCESSIVE

THREE S U C C E S S I V E

.

.

.

.

SERIES

.

LESSONS

O F TWELVE

.

.

.

General Nature of the Study of Group Learning.

LESSONS

.

19

.

. 19

Basic Assumptions Concerning the Range Unit of Score

. 19

Specific Purposes of the Study of Level and Trend of Score

.

.

.

.

.

.

.

.

.

.

20

Statistical Treatment for Analysis of Score-Level, Gain, and Learning Rate

.

.

.

.

.

.

.

.

Report of Results: Group Learning Topic I

20 .23

Level of Scoring Ability in First, Second, and Third Series of Lessons; Loss of Skill between Series

II

.23

Rate and Amount of Gain; Range and Group Difference .

III

.

.

as to Rate and Amount of Gain IV

.29

Early and Late Halves of the Series Compared .35

Large Group Difference in Score Contrasted with Small Group Difference in Gain; Gain as an Unsatisfactory Measure of Individual Achievement

V

.

.

.

.

.

.

Period of the Series Wien Individuals Tended to Make Their Respective Maximum Score Com-

.40

viii

On Measurement of Motor Skills pared with the Lesson in Which Group Maximum las Reached

43

General Summary of Group Learning

.46

Conclusions and Application of the Results

.48

III. FUNDAMENTAL CONSIDERATIONS RELATING TO LESSON RELIABILITY AND TO CORRELATION BETWEEN SCORES OF SUCCESSIVE LESSONS

50

Meaning of the Term "Reliability"

.50

Common Sources of I'nreliability and General Applications to Testing

.

.

.

.

.

.

.

.

50

The Estimate of Test Reliability and Needed Degree of Test Reliability for Evaluating Group and Individual Ability

51

Application of the Concepts of Test Reliability to the Study of the Reliability of the Archery Score

. 53

Basic Assumptions Concerning the Archery Score as These Relate to the Study of Le sson Reliability and to Correlation of Successive Lessons

.

.

.55

IV. LESSON RELIABILITY OF THE ARCHERY SCORE

.57

General Nature and Purpose of the Study of Lesson Reliability.

.

.

.

.

.

.

.

.

.

57

Procedure .

.

.

.

.

.

.

.

.

.

57

Definition of Minimum Degree of Reliability Needed for the Archery Score When Used for Classifying and Grading Individuals

.

.

.

.

.

.

.

.

Report of Results: Lesson Reliability Topic I

60 .64

Characteristics of Trend of Daily Reliability Coefficients Compared with General Trend of Daily Mean Score

II

.64

Evaluation of Units of Archery Score as to Their Suitability for Use in Testing Skill of Individuals

III

of Reliability IV

.70

Ranges Compared as to Degree and Variability 74

Beginner and Intermediate Groups Compared as Trend, Degree, and Variability of Daily Values of Lesson r.

.77

Table of Contents

ix

Sunmary of Results, Lesson Reliability of the Score

81

Interpretation of Results and Their Application to Testing and Guidance of Individuals and Groups

.

. 82

Suggestions for Further Study of Reliability of Archery. 86 PREDICTION OF SCORE LEVEL ATTAINED IN A SERIES OF LESSONS. 88 General Nature and Purpose of the Study of Lesson-toLesson Correlation of the Archery Score.

-88

Procedure

88

Report of Results . . . . . . . . 91 Topic I Degree and Significance of Correlation between Selected Lessons in Units of Range Score II

. 91

Attenuation of r: Sire of r Observed for Selected Consecutive Range-Lessons Compared with Reliability Coefficients of the Same Scores

III

.

.

.

-94

Fstimated Degree of Reliability of a Score Unit Consisting of Two Range Scores on Twentyfour Shots Each, Made in Consecutive Lessons 97

IV

Group Difference in Degree of Lesson-toLesson Correlation.

.

.

.99

V. Evaluation of Paired Range Scores and of Paired Lesson-Totals in Respect to Their Use for Prediction for Experienced Subjects.104 VI

Sunmary of Trend of Size of r in Relation to Early and Late Periods of the Series, to TimeInterval between Tests, and in Relation to Sire of Score Units

.

.

.

.

.109

Summary of Results from Lesson-to-Lesson Correlation

.Ill

Conclusions and Application of the Results to the Niatter of Evaluating Individual Skill and of Predicting ScoreLevel Attained

112

Suggestions for Further Study of Lesson-to-Lesson Correlation

.

.

.

.

.

.

.

.

.

.116

SPRING AND FALL SUBGROUPS COMPARED AS TO SCORE LEVEL, GAIN, AND RELIABILITY IN EARLY AND LATE PERIODS OF THEIR SERIES OF LESSONS .

.

.

.

.

.

.

.

.

.

117

O n Measurement

*

of

Motor

Skills

General Nature and Purpose of Spring-Fall Comparisons

. 117

Procedure .

.118

Report of Results: Spring-Fall Comparisons

119

Topic I

Score Level in First Four and Last Four Les-

II

Rate of Daily Gain, Amount of Gain in Score-

sons of the Series.

.

.

.

.

.

H9

Points, and Period of the Series When Individual and Group Peak Score Was Made III

Spring Compared with Fall IV

.

. 122

Degree of Variability of Lesson Reliability, .

.

.

.

126

Degree of Correlation between Selected Lessons, Spring Compared with Fall

.

.

. 131

Summary of Results: Spring-Fall Comparisons

.

.

. 131

Conclusions Relating to Season Effect on the Behavior of the Score and Applications to Testing and Guidance . 133 PART BEHAVIOR

OF

THE

SCORE

TWO WITHIN

A SINGLE

LESSON

VII. INTRODUCTION TO THE STUDY OF THE EFFECT OF SEQUENCE WITHIN THE LESSON UPON SUCCESSIVE UNITS OF SCORE.

.

.

. 137

Basic Assumptions Pertaining to Successive Levels of Efficiency When a Given Skill Is Performed Continuously over a Period of Time.

.

. 137

Application of Basic Assumptions Concerning Practice and Fatigue to Effective Performance in Successive Periods of an Archery Lessen

.

.

.

.

.

.

.

138

Application of the Foregoing Assumptions to the Analysis of Trend of Score within a Single Lesson

.

.

. 140

VIII. TREND OF SUCCESSIVE SMALL UNITS OF SCORE WITHIN A SINGLE LESSON OF USUAL LENGTH AND ONE OF DOUBLE LENGTH SHOT ENTIRELY AT RANGE 40

.

.

.

.

.

.

.

141

General Nature of the Study of Trend of Score within One Lesson

.

.

.

.

.

.

.

.

.

.

141

Specific Purposes of the Study of Single Range Lessons . 141 Procedure .

.

.

.

.

.

.

.

.

.

142

Table of Contents

xi

Report of Results: Standard- and Double-Length Lessons Shot at Range 40 •

•

•

. 145

Topic I

lest for Homogeneity of Set Means

.

. 145

II

Test for Homogeneity of Variance.

.

. 148

III

-

.

•

•

Significance of Difference between Set Veans, and Trend and Significance of Difference between Means of Units of Four Sets

IV

.

.

.

.

.

.

.

.

149

Test for Linearity of Trend of Successive Set Means: Fit of a Curve of Second Degree Compared with Fit of a Straight Line.

V

. 154

Period of the Lesson in Which Individuals Made Their Respective Peak Set Score Compared with Set in Which Group Peak Was Reached

155

Summary of Essential Results for Standard- and DoubleLength Lessons Shot Entirely at Range 40

.

. 157

Interpretation of Results and Their Application to Testing and to Guidance of Archery Classes.

.

. 1S7

Suggestions for Further Study of Single-Range Shooting 162 STUDY OF RANGE SCORES SHOT IN ROTATED ORDERS FOR SIX SUCCESSIVE LESSONS .

.

.

.

.

.

.

.

163

General Nature Gf tne Study of Range Scores Shot in Rotated Orders Procedure

.

.

.

.

.

.

.

.

.

163

.

.

.

.

.

.

.

.

164

Report of Results, Rotated Orders of Shooting Three Ranges . Topic I

.

.

.

.

.

.

.

.

168

Fesuits of Analysis of Variance by Treatment A.

II

. .

.

.

.

.

.

. 168

Revised Pattern of Analysis Used as Treatment P

III IV

Results of Analysis of Variance by Treatment B. . . . . . .

171 172

Tests of Difference between Range-Order f.ieans and Contrast of Trend of Difference for Successive Means of Ranges 30, 40, and 50

172

On teasurement

XI J

V

of Motor S k i l l s

Supplementary Report on Heather Conditions 177

in Relation to Group Difference in Score Summary of Essential Results for Rotated Orders of .

17g

Application of the Results to Testing and Guidance

Shooting the Ranges

.

.

.

.

.

.

. 180

Suggestions for Further Study of Rotated Orders of Shooting

.

.

.

PART SUMMARY

AND

.

.

.

.

.

.

181

THREE

EVALUATION

OF

THE

STUDY

X. GENERAL SUMMARY OF RESULTS, THEIR APPLICATION TO TESTING CERTAIN TYPES OF MOTOR SKILLS, AND CRITICAL EVALUATION OF THE STUDY

.

.

.

.

.

.

.

.

.

185

Part One: Trend and Reliability of the Daily Score in Three Successive Series of Twelve Lessons Each .

. 185

Part Two: Behavior of the Score within the Single Lesson .

.

.

.

.

.

.

.

.

.

188

Conclusions from the Study of Archery Scores, Stated in Terms of Application of the Pesults to the Testing and Guidance of Individuals and Groups.

.

. 190

Critical Evaluation of the Study .

.

.

.

.

199

Suggestions for Further Study

.

.

.

.

203

CLASSIFIED BIBLIOGRAPHY

.

LIST OF SUPPLEMENTARY TABLES

.

.

. .

.

.

.

.

205 209

LIST

OF

TABLES

G r o u p Learning 1

Range Means for Early, Mid-Season, and Late Periods of the Series,

2

for Beginner,

Intermediate, and Advanced Groups

24

G r o u p Difference in R a n g e Means, Showing Relative Status of Beginners, Intermediates, and Advanced in Scoring Ability at Stated Periods of the Series of Twelve Lessons

.

3

The Short Test of G r o u p Ability: Range Means for First Two,

4

Group Difference in M e a n Score on the Short Test of Paired

5

Rate of Daily Gain: Values of b y j

6

G a i n in Score: Score Increase from First Two to Mid-Series

Mid-Series Two, and Last Two Range-Lessons . Range Lessons.

.

Two Range Lessons,

.

.

.

.

.

.

.

.26

.

28

and Their Significance

. 28

from Mid-Series Two to Last Two, and

from First Two to Last T w o Range L e s s o n s 7

. 25

.30

Range Difference in Rate of Daily G a i n .

.

.

8

Group Difference in Fate of Daily G a i n .

9

Group Difference in G a i n in Score and in Decrease of G a i n

.32 .32

from Early to Late L e s s o n s

.

.34

10

Early and Late Halves of the Series of Lessons Compared as

11

Intermediate and A d v a n c e d Groups Compared as to Rate of

to Rate of Daily G a i n for Intermediates and Advanced .

. 37

G a i n in Early and Late Half Series and as to Decrease of .

-37

12

Relationship between Score and G a i n Subsequently Made .

Rate from Early to L a t e P e r i o d

.

.

. 42

13

Means of Lessons in W h i c h Individuals Made Their Respective Peak Scores of the Series Compared with L e s s o n in Which Group Peak V e a n »as Made

.

.

.

.

-44

L e s s o n Reliability 14

Minimum Degree of Reliability Requisite in a Score Unit That Is to Be U s e d as a Test to Evaluate the Ability of uals

15

.

.

.

.

.

.

.

.

.

.

Individ.

62

Beginners: Lesson R e l i a b i l i t y of Successive Range-Lesson Scores

.

.

.

.

.

.

.

.

.

.

.

65

* JV

O n Measurement

of Ifotor

Skills

16

I n t e r m e d i a t e s : L e s s o n R e l i a b i l i t y of S u c c e s s i v e

17

F r e q u e n c y w i t h W h i c h E s t i m a t e d C o e f f i c i e n t s of

L e s s o n Scores.

.

Range-

.

.

.67

Reliability,

for an E n t i r e L e s s o n of T w e l v e S e t s of Six S h o t s at

One

R a n g e , R e a c h e d or E x c e e d e d S t a t e d C r i t e r i o n V a l u e s o f r 18

Group Difference,

Intermediate - Beginner,

S e r i e s V a l u e s of r oe

. 7' 9'

20

Level

Correlation between Selected Lessons Score

for B e g i n n e r ,

Intermediate,

R e l i a b i l i t y of V a l u e s of

in U n i t s o f

Range

and Advanced Groups.

r for B e g i n n e r ,

. 92

Intermediate,

and

Advanced Groups 21

.93

C o r r e c t i o n of r for A t t e n u a t i o n :

V a l u e s of

r Observed

for

S c o r e s of C o n s e c u t i v e L e s s o n s C o m p a r e d w i t h E s t i m a t e d g r e e of L e s s o n R e l i a b i l i t y 22

of S a m e S c o r e s

secutive Lessons Group Difference

.

.

.

in V a l u e s of

W e a n s o f R a n g e V a l u e s of of B e g i n n e r s ,

.

S i z e of N e e d e d D i f f e r e n c e

.

and A d v a n c e d .

.

.

.

for

.

.

.

of the S e r i e s ,

.

. and

28

.

.

.

Spring-Fall Difference Four Lessons

.

.

for I n t e r m e d i a t e

.

.

and

.

106

and

in

Advanced .

.110

Comparisons

in M e a n Score o f F i r s t F o u r .

.

103

Periods

.

Spring-Fall

.102

.

to T i m e - I n t e r v a l b e t w e e n L e s s o n s ,

R e l a t i o n to L e n g t h of T e s t Groups

.

of

.

.

G e n e r a l L e v e l of r in R e l a t i o n to E a r l y a n d L a t e

.

Status

for I n t e r m e d i a t e

27

.

.101

Significance

C o r r e l a t i o n of P a i r e d L e s s o n - T o t a l s .

98

Com-

Intermediate,

26

Advanced Groups

.

in D e g r e e

.

in V a l u e s of r,

.

in C o n -

.

for S i g n i f i c a n c e .

in C o m p a r i n g B e g i n n e r ,

and Advanced G r o u p s

.95

Consisting

r As E s t i m a t e s o f R e l a t i v e

Intermediates,

at 01 a n d 05 L e v e l s ,

.

De.

r for C o r r e l a t e d L e s s o r s

Lesson-to-Lesson Correlation. 25

.

Shots Each, Vade

.

p a r e d w i t h S i z e of D i f f e r e n c e N e e d e d 24

.

E s t i m a t e d D e g r e e of R e l i a b i l i t y of a S c o r e U n i t of Two Range Scores on Twenty-four

23

.73

and

.

P r e d i c t i o n of Score 19

in D a i l y

.

.

.

.

and Last .

.

120

Table of Contenta 29

xv

Spring-Fall Difference in Rate of Daily Gain in Early and Latter Half-Series

.

.

.

.

.

.

.

.

123

30

Spring-Fall Difference in Gain in Score Points in Early

31

Spring-Fall Difference in Daily Values of r o e , Estimating

and Latter Palf-Series

124

Difference in Degree of Lesson Reliability

.

.

. 127

32A Spring-Fall Difference in r o e , Extreme Early and Late Lessons of Series

.

.

.

.

.

.

.

.

129

32B Summary of Direction and Significance of Spring-Fall 33

. . . . . . . . Difference in roe Spring-Fall Difference in Degree of Correlation between

129

Selected Lessons, Early Spring versus Early Fall, Late Spring versus Late Fall

.

.

.

.

.

.

.

132

Standard- and Double-Length Lessons Shot Entirely at Range 40 34

Test of Homogeneity of Means of Sets of Six Shots, All at Range 40

.

.

.

146

35

Chi Square Test for Homogeneity of Variance of Set Scores. 148

36

Means of Sets of Six Shots at Range 40 and Means of Units of Four Sets; Period of Lesson during Which Individual Peak Score »as Made

37

.

.

.

.

.

.

.

.

150

Double Lesson: Significance of Difference between Means of Units of Four Sets.

.

.

.

.

.

.

.

152

Range Scores Shot in Rotated Sequences 38

Pattern for Analysis of Variance by Treatment A.

39

Treatment A: Variances and Significance Ratios for Factors

40

Treatment B: Variances and Significance Ratios for Factors

in Range Rotation in Range Rotation

. .

. .

. .

. .

. .

. .

167 . .

. 169 .

173

41A Order Means for Ranges 30, 40, and 50, and for All Ranges Combined

.

.

.

.

.

.

.

.

.

.

175

41B Significance of Difference between Range-Order Means, Treatments A and B

.

.

.

.

.

.

.

175

XVi

O n Measurement

LIST

of OF

Motor

S k i l l s

DIAGRAMS

1

Beginner Grgup: Daily Range-Lesson Values of r 1 I .

.66

2

Intermediate Group: Daily Range-Lesson Values of r,j

.68

Chapter INTRODUCTION:

NATURE TO

OF

THE

I

ARCHERY

PRESENT

AND

GENERAL

APPROACH

STUDY

THE NATURE OF ARCHERY AND COMMON CONCEPTIONS CONCERNING I T S

SCORE

B r i e f D e s c r i p t i o n of A r c h e r y A r c h e r y has b e e n w i d e l y and c o n t i n u o u s l y practiced

for m a n y c e n -

t u r i e s . O r i g i n a t i n g in a n t i q u i t y t h r o u g h w a r f a r e and the hunt,

and

f o l l o w e d in some form or other in p r a c t i c a l l y e v e r y part of the a n cient and m o d e r n world, feat of skill

it is at present

for recreational

followed p r i n c i p a l l y as a

purposes.

T h e p o p u l a r i t y of a r c h e r y in the physical e d u c a t i o n p r o g r a m and in r e c r e a t i o n is i l l u s t r a t e d b y the a c t i v i t i e s of the N a t i o n a l A r c h e r y A s s o c i a t i o n and b y the a t t e n t i o n g i v e n in its p u b l i c a t i o n s to the a r c h e r y c l u b s in all sections of the c o u n t r y ; (8'7"20;9)*

by

the work of a s u b - c o m m i t t e e o n a r c h e r y s p o n s o r e d b y the N a t i o n a l S e c t i o n o n W o m e n ' s A t h l e t i c s of the A m e r i c a n A s s o c i a t i o n for H e a l t h , Physical Education,

and R e c r e a t i o n ; b y the w i d e p a r t i c i p a t i o n

p o s t a l and t e l e g r a p h i c tournaments, p a r t i c u l a r l y e g r a p h i c tournament

for c o l l e g e women,

shooting

and college,

form w h i c h p r e d o m i n a t e s

one

year.'®)

is the form most w i d e l y u s e d in the camp,

and b y clubs and other

tel-

for w h i c h a p p r o x i m a t e l y

h u n d r e d c o l l e g e s submit team scores every Target

in

in the annual

recreational groups.

school,

It is

this

in c o m p e t i t i o n s c o n d u c t e d b y national, state,

and local a r c h e r y a s s o c i a t i o n s and c l u b s . ( 5 : 1 6 1 * 7 5 ' 7 : 1 6 3 " 7 8 • 9 ) Target

s h o o t i n g u s u a l l y c o n s i s t s of shooting a standard

T h e r e are v a r i o u s Rounds,

e a c h calling

n u m b e r of sets of six shots at g i v e n Ranges, get,

•

The

numbers

ography, lowing not

distances

from the

in s p e c i f i e d seouence. The shortest o f f i c i a l Round

shooting seventy-two

the

the

given

colon in

in

first

the

calls

tar-

for

arrows.

parentheses number

Round.

for the shooting of a s t a t e d

relate

given

representing bibliographic

being

the

to

the

that

specific

reference.

of

numbered the

pages

references

reference in

and

instances

in the

where

the

Bibli-

numbers pages

fol-

are

2

On Measurement

of Motor

Skills

The manner of conducting Round shooting is well established by long tradition. The score is objectively measured and can be accurately recorded since the arrow remains fixed in the target until drawn. The score is commonly accepted as a valid measure of the archer ' s s k i l l . < • 2 : 1 4 : 1 0 > That the score should be so regarded

seems

quite reasonable, considering the nature of archery and of the conditions under which Round

shooting is necessarily conducted.

Basic Assumptions Concerning the Controlled Nature of Target Shoot ing and Commonly Accepted Conceptions Regarding the Archery Score The fundamental thesis is that in compar ison with activities, accurately skill

archery recorded

of the

is highly score

standardized

is a valid

other

and controlled,

and reliable

measure

sports and

its

of the

archer.

This thesis underlies the selection of the present

field of study

The essential points that support it are presented in the following statements. For more detailed information, the reader is referred to the literature on archery technique, tackle, and on the conduct of Round

shooting.

1. The act of shooting is highly routinized and uniform as to basic techniques of execution and the archer has various guides to exact

performance.

The s t a g e ? in making a shot are well d e f i n e d and follow one another in a s t a t e d sequence. S u c c e s s i v e s h o t s a r e made under the same r o u t i n e . S t a t e d numbers o f arrows a r e shot a t s p e c i f i e d d i s t a n c e s ,

in given

sequence.

P e r i o d i c r e l a x a t i o n o c c u r s a t evenly spaced i n t e r v a l s , which a r e s i m i l a r all

for

a r c h e r s who shoot a s t a t e d Round.

Archery t a c k l e i s made to e x a c t s p e c i f i c a t i o n s and c o n t i n u e d u s e o f the same s e t o f t a c k l e i s a f u r t h e r a i d to development o f c o n s i s t e n t performance. C e r t a i n lanrfcnarks on the t c c k l e and on h i s person a i d the a r c h e r in a c h i e v i n g from shot to shot an e x a c t r e p e t i t i o n o f the a c t s involved in s h o o t i n g an arrow. Use o f an aiming d e v i c e i s a customary p r a c t i c e . By means o f a simple measuri n g d e v i c e , the aim-marker can be r e p l a c e d a t the proper p o i n t on subsequent days.

2. The archer's score is the oroduct of his own unimpeded effort he is completely in command of his own performance. The s h o o t i n g problem i s simoly to h i t for the s t a t e d d i s t a n c e .

the t a r g e t , u s i n g the aim-marker

set

ion

Introduci

3

The archer works independently in making h i s shot.

I n f l u e n c e o f o t h e r s i s at

a minimum. 3. T h e

archer's

The o f f i c i a l

score

target

is o b j e c t i v e l y

and accurately

established.

face has f i v e a c c u r a t e l y marked scoring areas.

The arrows remain in the t a r g e t u n t i l drawn and the score value o f each i s recorded

individua1ly.

A score in any o f the o f f i c i a l Rounds customarily shot i s based on a minimum o f seventy-two shots, hence Round shooting presumably c o n s t i t u t e s a t e s t which i s comprehensive enough to j u s t i f y i t s being considered as a measure o f the a r c h e r ' s ski 1' at the time such score was made. Repeated shooting o f a stated Round shows improved records, hence records made over a p e r i o d o f v e l o p i n g s k i l l of 4.

Extraneous

formance

of

the

successive

time are presumed to measure the gradually de-

the s u b j e c t . sources

of

variation,

individual,

Automatic c o n t r o l o f

are

at

the experiences o f

which might

a minimum

influence

the

per

archery.

the archer w h i l e engaged in

a Round i s p r o v i d e d by the standardized nature of The a c t o f shooting i s o f i t s e l f

in

shooting

that Round.

h i g h l y r o u t i n i z e d and i s independently per-

formed by the i n d i v i d u a l . Unusual c o n d i t i o n s in the shooting s i t u a t i o n , such that adjustment to them i s principles.

as may a r i s e

from weather,

The p r i n c i p a l or only adjustment o r d i n a r i l y c a l l e d

adjustment o f

are

favored by the a p p l i c a t i o n o f already 1 earned for is

slight

the p o i n t - o f - a i m .

F l u c t u a t i o n s in score which occur from day to day may with good reason be a s c r i b e d p r i m a r i l y to v a r i a t i o n s within the i n d i v i d u a l . Such v a r i a t i o n s normally occur in a l l i n d i v i d u a l s and are met by a l l researchers when d e a l i n g with human m a t e r i a l . Because, in a l l other r e s p e c t s , archery i s h i g h l y standa r d i z e d and r o u t i n i z e d , sources o f extraneous v a r i a t i o n are thought to be at a minimum. 5.

A

score

the m e a s u r e

in a of

standard

the

event

archer's

o r Round

is c o m m o n l y

accepted

as

skill.

The score f o r a s t a t e d Round represents a standard shooting dose, done under c o n d i t i o n s that are very s i m i l a r f o r a l l archers, and hence i t has an accepted meaning to archers elsewhere. Records o f n a t i o n a l ,

s t a t e , or l o c a l

tournaments are a v a i l a b l e

f o r compari-

son at various l e v e l s o f competi t i o n . 6. A d m i n i s t r a t i v e so as

to

take

ardization of

full the

controls advantage

conditions

in guidance of

of

groups may be

the o p p o r t u n i t y

under

which

the

for

planned

further

shooting

is

stand-

done.

P a r t i c u l a r l y in handling groups, i t i s e n t i r e l y f e a s i b l e to f o l l o w c e r t a i n procedures f o r o r g a n i z a t i o n and guidance so as to achieve c o n d i t i o n s that, to a high degree, are a l i k e f o r a l l s u b j e c t s . Such c o n t r o l s r e l a t e to the type o f t a c k l e p r o v i d e d , to t a c k l e assignment, to c l a s s i f i c a t i o n o f archers

On Measurement

4

of

Hot or

Skills

in t a r g e t groups, to methods of r e c o r d i n g s c o r e s and p l a c e m e n t of aim-marker, to t e a c h i n g p r o c e d u r e , and to m o t i v a t i o n . P r o c e d u r e s f o l l o w e d w i t h t h e s u b j e c t s u s e d in t h i s s t u d y were adopted a f t e r c o n s i d e r a b l e p r e l i m i n a r y p l a n n i n g and t r i a l u s e . These a r e d e s c r i b e d u n d e r t h e t o p i c , Sources and Nature of Data, in a f o l l o w i n g s e c t i o n of t h i s c h a p t e r . The foregoing statements, supplemented by further description elsewhere in this report, lend weight to the basic assumption that archery is inherently highly standardized. Many of the possible sources of variation, such as operate more or less constantly in other sports activities, are forestalled or minimized at the outset. E x t r a n e o u s Sources of Variation and Means by Which Their Effect Was Moderated

Weather

in the Present

Conditions.

Study

Outdoor archery is subject to weather

influ-

ence, particularly to strong wind when long range shooting is done. Marked change of temperature may affect the weight

of the bow

(force required to draw it), but such effect is believed to be slight in bows of lemonwood, the most common type. Probably the archer is also somewhat affected by discomfort on cold days, although this would not necessarily affect his consistency or scoring ability. Weather-effect on arrow-flight

can be compensated

for

to a considerable extent by readjustment of the aim-marker once the archer has become aware of the unusual

condition.

Over a period of time, variations due to weather may be expected to compensate

for one another, especially so when scores have been

drawn from several years. Weather differences would have a compensating effect on mean score, although individual variability

from

day to day might be increased. In using cases from one institution, weather-effect

in a given season is presumably experienced by all

subjects to a very similar degree.

Teaching

and Environmental

Influences.

Extraneous

disturbances

that may occur, the psychological effect of observers or the reaction of the subject to the presence or activities of the teacher, are elements which might cause momentary deviation in degree of control.

It may also be assumed that while receiving

instruction

the individual will vary somewhat in score made in successive shots. Arrow-flight

is a product of the manner of controlling

the

tackle, and the archer must of necessity make the finer adjustments

Introduct

5

ion

of his aim-marker w i t h reference to his manner of controlling his tackle, particularly so at the crucial instant of anchoring and releasing. If he makes a correction in form, he will often need to readjust his aim-marker slightly. Until he adjusts his aim,

several

shots m a y make low or no score, despite the fact that they m a y have b e e n executed with improved technique. However, the routinized nature of archery, together w i t h the excellent possibilities afforded for adherence to standardized procedures in group teaching and guidance, as subsequently described, serves to aid materially in the attainment of the goal of providing a learning environment and a series of experiences that are the same for all subjects. Under such a considered plan of procedure, there is good reason to believe that group teaching exerts little differential effect o n individuals and that variation in successive scores c a n be ascribed p r i m a r i l y to variations among individuals. Inter-Institutional

Variation.

A recent survey of over one hun-

dred colleges offering archery for w o m e n disclosed several possible sources of v a r i a t i o n that might affect achievement classes.Length

in archery

of season, frequency and d u r a t i o n of class

periods, size and classification of groups, methods of teaching and progression, and similar factors, appear to constitute or practices that differ from one college to

conditions

another.(

1 6 :

I3)

Becoming aware of such sources of variation, the present writer therefore sought to unify, to the m a x i m u m feasible extent, conditions under w h i c h scores u s e d in this study were made. tutional variation is ruled out in the present Individual

Differences

in Subjects.

Inter-insti-

study.

Potential capacity in any

activity presumably resides not only in those inherent mental, physical, and emotional traits which set for each individual his own particular ceiling of performance, but relates also to transitory states w h i c h condition the degree of control that the subject may be able to exercise at any given time. Assuming that e a c h individual has a certain capacity for successful performance, tions in fatigue, emotional tone, interest, and in general of well-being, manifest themselves from d a y to day in all

variastate

subjects,

and may b e expected to affect quality of performance o n successive

6

On Measurement

of Motor Skills

days. Such sources of variation are met by all researchers when dealing with human material. REVIEW OF LITERATURE The field of measurement and testing is so comprehensive in scope and so detailed in nature that to attempt to review the literature on any aspect thereof is not feasible in a report of the scope of the present one. In lieu of attempting to report on any selected references pertaining to testing and measurement, recourse is taken to listing certain helpful sources, particularly texts and bibliographies. Such a list of selected references is included in the Bibliography of this report. Previous Studies of Archery The literature on archery is extensive in respect to history, the making of tackle, techniques of performance, and teaching methods. The few studies that have been made of measurement in archery are of value as a matter of interest, and for suggestions concerning certain areas in which further work might be done. An early study by Lashley was of trial-and-error shooting. Score was based on the number of inches from the center of the target to the point where the arrow struck. Accuracy was found to be low at the outset, then to increase rapidly for a period of time, and subsequently to attenuate in rate of its increase. The total time spent in shooting was found to be more effective in terms of score when divided into short practice periods at frequent intervals than when concentrated in longer and fewer periods.( 1 7 :

los

"28)

Several studies of archery for college women have been made by Hyde. Results from an earlier study^ 15 ^ are incorporated in a more comprehensive and recent r e p o r t / 1 4 ^ Another study was a survey of teaching methods and organization of archery/ 1 6 ) and still another proposed achievement standards for beginners from data drawn from a large number of institutions/ This writer believes that the achievement scale thus developed is of limited value, since the institutions contributing data varied considerably as to time allotment for archery and the scores submitted represented different numbers of l e s s o n s / 1 6 ) Although

Int roduct ion

7

c e r t a i n factors that might easily affect rate of progress must be e x p e c t e d to differ from one institution to another, an achievement scale for beginners

should at least represent a stated number of

lessons. If a scale for advanced college women archers were desired, perhaps the best source of scores would be those

submitted

a n n u a l l y for the Intercollegiate Telegraphic Archery Tournament.^ 9 ^ If the colleges were grouped, not by geographic district alone, but in accordance w i t h length of archery season, including the factor of availability of facilities for indoor practice, and if a scale were developed for each group, certain major discrepancies affecting opportunity for shooting might be considerably reduced. E a c h institution could compare records of its advanced archers w i t h the scale for that group of colleges whose specifications best

repre-

sent its own situation. A comprehensive report by Hyde draws together the results of several pieces of her work done with college woman archers over a p e r i o d of y e a r s . T h e

object of this series of studies was to

d e v e l o p a standardized test for measuring achievement of beginner and advanced subjects, and to seek evidence of relationship w h i c h might exist b e t w e e n achievement in archery and other traits such as height, weight, motor ability rating, and mental ability. T w o groups of cases were treated. The first group,

numbering

seventy-five beginners and thirty-five advanced subjects, three weeks of instruction,

had

followed by shooting a practice test

and then a final test. The practice test consisted of 120 arrows at e a c h of four Ranges,

20, 30, 40, and 50 yards, each R a n g e be-

ing shot in four class periods of thirty arrows each, and in sequence; 20-yarH shooting being completed first, followed in order b y the longer Ranges. The final test consisted of two Rounds,

Columbia

each of twenty-four arrows at 50, 40, and 30 yards,

that order. No teaching was done during the test The second

group,

in

shooting.

d r a w n from the same institution but in a

subsequent year, numbered fifty-four unselected freshmen and twenty-three freshmen majoring in physical education. All of the second

group

were beginners.

They were treated like the first

group, excepting that 20-yard shooting was omitted. The principal findings of Hyde's study that are thought to b e

O n Measurement

8

of

Motor

Skills

of interest in connection with the worl' of the present writer are as

follows;(97-99)

Beginners of

the f i r s t group,

compared with those o f

n i f i c a n t l y exceeded in score at a l l Ranges,

the second

This was a t t r i b u t e d to the f a c t that the beginners o f the a d d i t i o n a l

group,

in both p r a c t i c e and f i n a l

sigtests.

the f i r s t group had had

t r a i n i n g o f shooting 130 arrows at 20 yards.

D i f f e r e n c e in i n t e r v a l between p r a c t i c e periods had no a p p r e c i a b l e e f f e c t on score. Mean score o f the Ranges in the f i n a l t e s t was c o n s i s t e n t l y higher than in the p r a c t i c e t e s t , in s p i t e o f the f a c t that e i g h t lessons intervened when 30 yards was not shot, four lessons when 40 yards was not shot. H i t l e r score in the f i n a l t e s t was ascribed to c a r r y - o v e r o f s k i l l from one Range to ano t h e r , a l s o to the fact that the subjects knew they were shooting a f i n a l test. Beginners showed a t y p i c a l learning curve, with low i n i t i a l accuracy, gain, and dimishing increment o f return front further p r a c t i c e .

rapid

Majors in physical education had very s i p i i f i c a n t l y higher motor a b i l i t y ing than had the unselected

rat-

freshmen, but only s l i g h t l y h i t l e r archery s c o r e .

C o r r e l a t i o n o f archery score with h e i g h t , weight, motor a b i l i t y r a t i n g was n e g l i g i b l e .

i n t e l l i g e n c e r a t i n g , and

Comparison was made of obtained r e l i a b i l i t y c o e f f i c i e n t s in the archery study, with r e l i a b i l i t y reported by other researchers f o r t e s t s i n v o l v i n g hand-eye coordination or accuracy. In comparison with f i v e such t e s t itesis, with rel i a b i l i t y c o e f f i c i e n t s ranging from .07 to .22, those f o r archery ranged from .73 to .86, f o r beginner and advanced s u b j e c t s .

Conclusions drawn by Hyde with reference to archery are as folJows;(14:97-101)

Archery s k i l l

seems to be unrelated to other

The archery t e s t i s d e s i r e d

to measure s k i l l

abilities. in a p r o g r e s s i v e s e r i e s o f

p r a c t i c e u n i t s riiich do not i n t e r f e r e with teaching. evaluate d i f f e r e n t methods of

I t could be used t o

teaching, or to c l a s s i f y

individuals.

Rirther work seems d e s i r a b l e on such aspects as: - - t e s t i n g experienced subjects with varying amounts o f previous i n s t r u c t i o n -- f a t i p j e - p o i n t in a lesson, so as to plan p r a c t i c e periods to produce maximum s k i l l -- h e i g h t , weight, and strength in r e l a t i o n to weight o f bow used and success a t t a i n e d -.- p s y c h o l o g i c a l f a c t o r s such as i n t e l l i g e n c e and emotional -- weather c o n d i t i o n s

stability

-- v a l i d i t y o f values assigned the d i f f e r e n t s c o r i n g areas o f extent to which scores are determined by chance.

the t a r g e t

The present study follows an approach somewhat different

from

that of Hyde. The object was not to standardize a test nor to develop achievement standards, but rather to study trend and reliability of the score within a single lesson, and from lesson to

Introduct ion

9

l e s s o n of three successive series. For the study of successive lessons of three series, the data were drawn over a period of six y e a r s for all groups, hence unusual weather conditions obtaining in any given year should not obscure the results. Whereas Hyde's subjects shot one Range o n l y for four successive lessons, and took u p the Ranges sequentially, those of the present study shot a standard Round in every lesson, with the exception of the beginner g r o u p in certain early season lessons. Two specific areas of work suggested b y Hyde have, however, b e e n undertaken, namely, a study of scores of experienced subjects having had different amounts of experience and a study of practice-and-fatigue effect within a single lesson. Another s t u d y ( 1 8 ) used a portion of the cases treated in the present one. The only finding of that study which might relate to the present work is that members of archery classes in the given institution were apparently a representative group in regard to their distribution among four classifications of general motor ability, even though a relatively substantial proportion, 31 percent, were either temporarily or permanently restricted as to choice of physical activity. In a recent study, Moffett sought to determine whether a significant difference in accuracy of direction resulted w h e n certain motor skills were performed at different distances from a target. (19) Shooting an arrow was included as one of the skills tested. The basis for discrimination was relative size of the angle of error. The target u s e d for several tests, including that of shooting an arrow, was 9 b y 10 feet in size, cross-sectioned in 6-inch squares. A 2 - i n c h circle was m a r k e d in the center of the target and the subjects were instructed to attempt to hit that mark. Six men, highly proficient in the skills tested, were subjects, and a minim u m of 100 trials per distance was exacted of each. The height of the center of the target w a s adjusted to the mean height of the point of release of the six subjects. Moffett's findings for shooting an arrow were as

follows:^ 1 9 1 4 7 8 )

"1. There are no significant increases or decreases in accuracy, as determined by the total angle of error, when the distance is increased. .. from ten yards to fifty yards w i t h increments of ten yards. The same statement holds for accuracy to the left of the center of the target.

10

On Measurement of Motor

Skills

• 2 , When the d i s t a n c e . . . is increased from ten yards t o twenty yards there i s a d e c r e a s e of accuracy t o the right of the c e n t e r of the t a r g e t , but an addit i o n a l increase of f o r t y y a r d s . . . , w i t h increments of ten yards, r e s u l t e d in no f u r t h e r inaccuracy in t h i s d i r e c t i o n . " 3 . Accuracy decreases above the c e n t e r of

the t a r g e t with an increase in the

d i s t a n c e . . . f r o m ten yards t o twenty yards. However, w i t h an increase from twenty yards t o t h i r t y y a r d s . . . ,

accuracy in t h i s d i r e c t i o n increases,

though a d d i t i o n a l yardage increases r e s u l t

al-

in no further increase in accuracy.

* 4 . Accuracy decreases below the c e n t e r of the t a r g e t w i t h an increase in d i s tance. . . from ten yards t o twenty yards, and a d d i t i o n a l increases in the d i s tance r e s u l t in increased inaccuracy in t h i s d i r e c t i o n up to and including the f o r t y - y a r d d i s t a n c e . "

Motfett's results pertain to increase or decrease of accuracy in terms of error above and below the center of the target and to left and right of center, whereas archery scores are not evaluated in terms of the quadrant in which they strike. Moreover, his unit of measurement and the size and arrangement of his target differed from those used in archery target - shooting, hence his results do not apply particularly to the problems undertaken in this study. PURPOSE AND SCOPE OF THE PRESENT

STUDY

The Nature of Archery as a Challenge to Choice of the Field of Study Interest in problems of testing achievement in physical activity and a questioning attitude toward some of the work reported in this field provided the original impetus of this study. The primary object was to gain insight into problems met in activity ing,

test-

not solely to study archery. Archery was selected because by

its nature it seemed to offer certain distinct advantages, particularly that certain sources of variation were eliminated at the outset and that certain others could be minimized. Considerations leading to the choice of archery were as follows: 1. The archery score represents the total outcome of individual performance and is generally accepted as a valid measure of skill. In most other sports the m u l t i p l i c i t y of

techniques i n v o l v e d and the

v a r i e t y o f p l a y s i t u a t i o n s and r e l a t e d s t r a t e ^ , essence o f lem of

a l s o the f a c t that the very

the game may be i n t e r - p l a y between opponents, complicate

finding a criterion

for s k i l l

t e s t s that represent the t o t a l nature o f lems are e l i m i n a t e d .

the prob-

and a l s o that o f d e v i s i n g a t e s t or the a c t i v i t y .

In archery,

The a r c h e r ' s score i s a prockict o f h i s

such prob-

independent

Introduction

il

performance of a s e r i e s o l a c t s that represent the t o t a l nature of the s k i l l s i n v o l v e d , and that are performed under c o n d i t i o n s that automatically are very l i k e for a l l p a r t i c i p a n t s . 2.

The

ardized many

routinized conditions

extraneous

nature under

of

archery

which

influences

it

that

and

the

relatively well

is n e c e s s a r i l y

might

exert

conducted,

differential

stand-

rule

effect

out on

individuals. In contrast to many other a c t i v i t i e s , in which every successive p i a y i n t r o duces a new s i t u a t i o n to which the s u b j e c t must react, in archery the nature and sequence o f the acts c a l l e d f o r , the rhythm and i n t e n s i t y o f a c t i v i t y , the i n t e r v a l s f o r r e l a x a t i o n , the c a p a c i t y o f the equipment f o r exact performance, and the p o s s i b i l i t y for s e c u r i n g an accurate record o f the s c o r e , are el ements which are very c l o s e l y s i m i l a r tor a l l subjects. Such f a c t o r s automatically r u l e out d i f f e r e n c e s in the d i f f i c u l t y o f the problems faced by di f ferent subj e c t s , and sources of e r r o r in tile score. Hence, the archery • c o r e , to a high degree, represents the a r c h e r ' s status ir. r e l a t i o n to that of h i s f e l l o w s . 3.

Many

is well

successive

scores

controlled but

and normal

situation

can be

that

seems

secured to

for e n j o y a b l e

the

in an environment

subject

participation

to be in the

the

that

natural

activity.

O r d i n a r i l y the process of securing repeated scores n e c e s s i t a t e s that much time be devoted to t e s t i n g , a l s o that s p e c i a l e f f o r t be made to c o n t r o l the environment. Under such c i rcums tances, opportunity tor tne subject to part i c i p a t e in the a c t i v i t y in the a p p r o p r i a t e play s i t u a t i o n 19 l i k e l y to be purtaixed. Moreover, the s u b j e c t i s l i k e l y to be aware of the f a c t that he i s being t e s t e d , and awareness o f being in a t e s t s i t u a t i o n i s l i k e l y to e x e r t a d i f f e r e n t i a l e f f e c t on i n d i v i d u a l s . Being h i g h l y r o u t i n i z e d and standardized, archery lends i t s e l f p a r t i c u l a r l y w e l l to control o f the s i t u a t i o n in which the shooting i s done, and to adherence to a s t a t e d plan f o r group guidance and i n s t r u c t i o n . To a high d e g r e e , as compared to other a c t i v i t i e s , c o n t r o l l e d conditions can r e a d i l y be maintained even «rtiile group i n s t r u c t i o n i s given. Hence, the s u b j e c t s are not e x p l o i t e d even though t e s t i n g may be q u i t e continuous — they can shoot under conditions which seem to them q u i t e a p p r o p r i a t e to the a c t i v i t y , and can be unaware o f the f a c t that they are being t e s t e d . In most other a c t i v i t i e s , i t would be q u i t e d i f f i c u l t to secure s u c c e s s i v e d a i l y scores made under s t a t e d conditions without so a l t e r i n g the p l a y s i t u a t i o n as to l i m i t s e r i o u s l y the s u b j e c t ' s experience in and enjoyment o f the a c t i v i t y . 4. Because of

of

the p r e s e n t

institutions. met

In

in testing,

a n d suggest

the work

standardized can be

addition, give

possible

for e l e m e n t s o f

skill

nature

expected certain

insight

into

approaches involving

to

of

archery,

to a p p l y

results may the behavior test

in

illustrate of

revision,

accuracy.

certain

to a r c h e r y

results other

problems

successive

scores,

particularly

so

12

On

Measurement

of

Motor

Skills

The results pertaining to score-level attained by the subjects used in this study will naturally apply only to subjects treated very much as were these. However, because the nature and conduct of archery target-shooting is likely to be nuch the same wherever it is done, regardless of details of method of teaching and guidance, instructors in other institutions should be able to apply certain findings to their own situations. They may derive suggestions for the selection of score-units that are likely to provide fairly accurate estimates of the skill of individuals at stated periods in a first, second, or third series of lessons, and for test adninistratian. They may become more critical of the meaning of a score, and more aware of sources of variation. If the methods of group organization and guidance in another situation are less well standardized than those described for the subjects here treated, then another instructor might well feel that even larger score-units should be used for testing than those found to be adequately reliable in the treatments here reported. Since archery represents a highly specific skill, the results from this study will probably apply only in a general way to testing elements of skill in other activities. However, the activity-teacher or researcher may well be interested in the behavior of s uccessive scores, may gain further insight into the meaning of a test score made at any stated time in a lesson or in a series of lessons, and may derive suggestions for further study of existing tests, particularly those for elements of skill involving accuracy of performance. A critical attitude toward the results of testing elements of skill which are inherently less amenable to control than is archery may be a worth-while by-product. Purpose The

and Scope of

terion

for

to a n y

skill

in d e t e r m i n i n g

cific

objectives were

1. T o for

2. T o

study three test

study

3. T o

4. T o

trend

of

score

successive lesson

score-units 5. T o a single tive

used

study

is u s e d

seemed as a

to

cri-

to b e o f

some

in t e s t i n g . T h e

spe-

to l e s s o n of a

twelve the

series,

lessons.

archery

score, w i t h

sources

out.

early

for p r e d i c t i n g

in t h e

the c o n t r a s t i n g

or

for

to

of

the p o s s i b i l i t i e s

end-series

series.

t r e n d of g e n e r a l w e a t h e r

as compared

in r e l i a b i l i t y

should be

trend

lesson,

followed

from l e s s o n

ruled

secured

find w h e t h e r

in g a i n ,

to be

series of

in s p r i n g c l a s s e s

fall c l a s s e s

those which

those which promised

reliability

investigate

in score,

are

the score

these:

from m e a s u r e s

ditions

and

procedures

of day-to-day variation

score

here

in w h i c h

in a r c h e r y ,

value

and

Study

specific problems undertaken

be prerequisite

and

the Present

to fall c l a s s e s w a s to such a degree that

given different

treatment

as

con-

reflected spring

regards

testing. of

successive

find w h e t h e r

scoring efficiency were

small units of

score m a d e

any clearly defined

reflected

within

s t a t e s of

in t h e l e s s o n of u s u a l

relalength.

Jntrocfuct

13

ion

The problems undertaken fall into two major types. The first type relates to the treatments made of daily score in successive lessons of three successive series; the principal object being to study group learning and to evaluate score-units of stated length as tests of group and individual ability and improvement. These problems are reported in Part One of the study, including Chapters II to VI. The second type consists of the treatments made of successive small score-units made within one lesson. Two single lessons were used to study practice and fatigue effect when all scores were shot at one distance, Range 40. In addition, a series of six test lessons was used to study the effect on the Range score of the sequence in which it is shot, the Ranges having been shot in rotated orders for six lessons. These two series of single-lesson treatments are reported in Part Two, including Chapters VII to IX. The work has been limited to the study of the behavior of the score. It is beyond the scope of this study to investigate physical and mental traits that may relate to the degree of success attained, or to analyze sources of variation in score, except as these were implied in the results. SOURCES AND NATURE OF DATA

Subjects and Data Used Subjects used were Wellesley College undergraduates who had taken one or more series of lessons in archery during the period 1935 to 1941 inclusive. From the entire population of archers of this period were selected all who had shot at least twelve out of a possible thirteen or fourteen lessons per season. Since the great majority reached or exceeded the twelve-lesson criterion, it is thought that the elimination of those who had shot fewer lessons did not bias the sample in any serious way. For the study of successive

lessons,

the usable cases numbered

258 beginners, 139 intermediates (second series), and 53 advanced (third series) subjects. Daily scores were used, each lesson ordinarily consisting of twenty-four shots each at Ranges 50, 40, and 30 (yards distance from the target). For the study of score within a single

lesson,

intermediate sub-

jects were used, 36 and 44 for the treatment of lessons shot

14

O n Measurement

of

Motor

Skills

entirely at Range 40, and 33 for the treatment of Range scores shot in rotated order. These were random samples of the total population of Wellesley College archers and, except

for special treatment

given at the time of securing requisite data, had been treated like all other subjects used. Conditions under Which the Scores Were Made In order to standardize conditions so far as was possible, procedures for grouD guidance were tried out for three years in advance of the six-year period represented in

data used

A stated plon

was adopted and conscientiously followed in all archery classes, under the suoervision of one instructor. It is believed that this plan was of material aid in capitalizing on the inherently well standardized nature of archery, and that the environment was to a high degree identical for all subjects. The following procedures were e^olnved: Be pinner

and

at o p p o s i t e Each

e x p e r i e n c e d subjects

sid*»s o f

experience-group

gets,

since

Group

instruction

as

numbered

u