BY DAVID WECHSLER

INTRODUCTION

The WAIS-R extends the line of test development that begin with the publication of form 1 of the wechsler Bellevue intelligence scale in 1939, and continued with it revision, the WAIS published in 1955.

WHAT INTELLIGENCE TEST MEASURES?They are design to measure major mental abilities.“Intelligence is the aggregate or global capacity of

the individual to act purposefully, to think rationally and to deal effectively with his environment (Wechsler, 1944, p. 3).”

VERBAL SCALE

Picture completion

20 14 1 5

Picture arrangement

10 6 0 4

Block design

9 9 0 0

Object assembly

4 4 0 0

Digit symbol

93 90 0 3

PERFORMANCE SCALE

STANDEREDIZATION OF SCALEA stratified sampling plan was adopted to

insure that representative proportions of various classes of adult would be included in the standardization sample.

AgeSexRaceGeographic RigionOccupationEducationUrban/Rural Residence

DERIVATION OF SCORESDevelopment of scoring rules.

Rules for starting and discontinuing tests.

Bonus for fast performance.

Age group

N Verbal scale Performance scale

Full scale

MEAN

SD MEAN

SD MEAN

SD

16-17 200 50.72 12.52 47.37 9.49 98.10 20.47

18-19 200 51.72 12.66 46.92 10.09 98.65 20.99

20-24 200 58.62 13.61 51.14 10.27 109.76

22.09

25-34 300 61.42 15.26 49.89 11.63 111.31

25.27

35-44 250 57.47 15.56 45.26 11.97 102.74

26.12

45-54 250 58.12 14.89 42.09 11.34 100.22

24.66

55-64 160 55.59 14.68 38.19 10.80 93.78 24.05

65-69 160 53.54 15.78 33.81 10.59 87.35 24.81

70-74 160 51.50 14.28 30.62 8.40 82.12 20.85

INTERPERTATION OF IQQuantitative interpretation:

The verbal, performance, and full scale IQ distribution were constructed to have means of 100 and SD of 15 within each of 9 age group.

Classification of intelligence:In using qualitative and diagnostic categories

to describe levels of intelligence it is desirable to assign numerical limits to each category.

Properties of scaleReliability :

The reliability of a test refers to the accuracy of its measurements or put another way to the extent of agreement between score obtained from two or more administrations of the tests to the same subject.

Two types of data are offered Reliability coefficients Slandered error of measurements

Properties of scaleValidity :

The initial evidence of the validity of the Wechsler Adult scales stems from the procedures used to determine the content of the original W-B scale.

General directions for administrationTiming the itemsProbing of responses

General directions for scoringIf a response is intended to replace an earlier

response, the earlier response should be ignored and the later one scored.

Any spoiled response is scored “0”If two independent answers are given to a

question, the examiner must ask which answer is intended

If a subject gives two or more answers to a questions, non of which spoils the response, the best answer of the group should be scored