Understanding Intelligence Tests

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Understanding Intelligence Tests Powered By Docstoc
         Vanessa D‟silva
         Clinical Psychologist, Learning Disability Clinic, KEM Hospital
What Is Intelligence?
   Ability to adjust to different situations.

   Ability to learn.

   Ability to engage in abstract thinking.
Definition By Wechsler

“The aggregate or global capacity of the individual
    to act purposefully, think rationally and deal
          effectively with the environment.”

   Aggregate and Global implies it is revealed by an
    individual behaviour as a whole.

   Purposeful implies that intelligent behaviour is goal
    directed which is based on drives and incentives.
Theories Of Intelligence

Spearman’s ‘g’ Factor   Thurston’s Group      Thorndike’s
      Theory             Factor Theory     Multifactor Theory
Spearman‟s „g‟ Factor
Spearmen‟s „g‟ Factor Theory
   Spearmen arrived at the concepts based on inter
    correlations between different tests he administered
    to his subjects. These were as follows:
     Analogies.
     Completion.
     Understanding   Paragraphs.
     Opposites.
     Instructions.
     Resemblances.
     Inferences.
Spearmen‟s „g‟ Factor Theory
   r = .55 Analogies and Opposites.
   r = .32 Instructions and Resemblances.
   However, the correlations were not perfect positive
    correlations. This led Spearman to postulate the
    existence of „s‟ (specific) factors.
   A specific factor is one that is characteristic of a
    single mental task and is unique from other mental
Thorndike‟s Multifactor Theory
   Intelligence is composed of a multitude of highly
    specific factors.

   Two mental tasks will be highly correlated if they
    shared these minute elements.

   Thus Thorndike implicitly accepts the existence of
    group factors.
Thorndike‟s Multifactor Theory
   Thorndike developed the CAVD test i.e.
    C  – Sentence Completion.
     A – Arithmetic Reasoning.

     V – Vocabulary.

     D – Following Directions.

   Each of the subtests measured different aspects of
    Abstract Intelligence.
   Significant      positive correlations were found
    between subtests thus indirectly giving the „g‟ factor.
Thurston‟s Group Factor Theory
   According to Thurston mental action have in common
    primary factors or group factors.

   These primary factors are shared by some mental
    tasks and not others.

   They serve to bind mental activities into separate
    groups and they are relatively pure in nature.
Thorndike‟s Multifactor Theory
   He administered the following tests (Primary Mental
    Abilities Test):
     N – Number Fluency.
     W – Word Fluency.
     V – Verbal Comprehension.
     S – Spatial.
     M – Memory.
     R – Reasoning.
     P – Perceptual Speed.

   However, inter correlations were significant high positive
    ones. This led Thurston to propose the existence of a
    second order „g‟ factor.
   All three theories ultimately arrive at considerable
    agreement with each other.

   Critics of such theories believe there no real
    difference between „general‟, „group‟ and „specific‟

   These differences emerge simply because of the
    number and nature of tests on which a factor
    analysis is conducted.
DSM –IV TR Classification
   IQ 71-84
       Borderline Intellectual Functioning.

   IQ 50 -55 to approx. 70
       Mild Mental Retardation.

   IQ 35-40 to approx. 50-55
       Moderate Mental Retardation.

   IQ 20-25 to approx. 35-40
       Severe Mental Retardation.

   IQ Below20-25
       Profound Mental Retardation.
Wechsler‟s IQ Classification
   IQ 90 – 110
       Average Intelligence.

   IQ 110-120
       Above Average Intelligence.

   IQ 120-130
       Superior Intelligence.

   IQ 130 and above
       Very Superior Intelligence.
Salient Features Of IQ Tests
   Standardized instructions for test administration.
   Time limit allotted to each items.
   The item limit after which test is to be discontinued.
   Evaluative criteria together with specimen answers.
   Scheme of scoring.
   Bonus scores to be given for rapid performance.
Wechsler‟s Intelligence Scale For
Children By Dr M. Bhatt
   This scale includes
    12 separate sub-
   Age 5+ to15+
   It yields Verbal IQ,
    Performance IQ
    and Full Scale IQ.
WISC Scoring
   Raw scores obtained for each subtest are converted
    to Scaled Scores.

   Scaled Scores are converted to Verbal IQ and
    Performance IQ.

   The sum of Verbal IQ and Performance IQ Scaled
    Scores give the corresponding Full Scale IQ.
LD Features On The WISC
   The difference between Verbal IQ and Performance IQ
    is 15 or greater it indicates presence of extraneous

   Resulting Full Scale IQ obtained is considered not a true
    indicator of intelligence.

   Scores on the ACID profile lower than intra test average
    i.e. the scores on Arithmetic, Information, Coding and
    Digit Span.
WAIS-R Block Design Task
Seguin Form Board (SFB)
   Aim: The individual has to insert geometrical
    shaped blocks into corresponding recesses as
    quickly as possible.
   Norms available from 3years to 20 years.
   Used particularly for young children and
    supplemented with other tests.
   Advantages:
     Spontaneous   arousal in children.
     Amenable & brief.
     Valid „g‟ obtained.
Kamat Binet Test Of Intelligence (KBI)

   The original test was the Stanford Binet scales.

   This test was developed based on the concept of
    age norm.

   Kamat undertook a revision of the Stanford Binet
    Scales to suit Indian conditions.

   The tests has subtests from Age III to XXII.
Administering The KBI
   Begin with the tests of the year of the child.

   He/ She may pass on some but fail in few.

   Work upwards till the child fails on all items.

   Then work below the child‟s chronological age until
    all items are passed.
Scoring And Interpreting The KBI
   For each item passed the child earns a credit of
    2 months, 4 months or 6 months depending on the
    corresponding age.

   IQ = Mental Age × 100
          Chronological Age

   The IQ thus obtained is classified.
Raven‟s Progressive Matrices
Raven‟s Progressive Matrices
   It is a test of observation and clear thinking.
   Measures ability to form perceptual relations,
    reason by analogy independent of language and
    formal schooling.
   It consists of 5 sets of 12 items each.
   Each item contains a figure with a missing piece.
   Norms are available for age 6 – 16.
         Vanessa D‟silva
         Clinical Psychologist, Learning Disability Clinic, KEM Hospital

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