Group-15Arka Prabha RoySouptik BaruaPratiti MandalDeepanshuPankaj Pansari

Psychometric Determination of Mental Retardation using Soft Computing

What is Psychometric Analysis?

PSYCHOMETRIC TESTING

Psychometry =

“Psyche” (mind) + “Metron” (measure)

Which means measuring the psychological abilities of a person. Psychometric Testing is an important

objective tool that helps in assessing the personality traits of an individual and hence is the pillar of

Psychology.

The field of Psychometry uses several tests and questionnaires according to the necessity of the educational, employment or health care settings.

These methods are tools that provide fundamental information about the person’s abilities and are in no way similar to the attainment tests and career assessment tests.

The emphasis in Psychometric Testing is not on scoring or knowledge gain but the distinguishing features of an individual.

Types of Psychometric TestsThere are two types of Psychometric Tests :-

1.Aptitude or Intelligence Tests Assess a person’s general cognitive abilities of verbal, numerical, logical reasoning, capability to learn new things and even special abilities

2.Personality Tests

Assess behavioral and personally traits like sensitivity threshold, motivation, socialization and ability to deal with challenging situations

Psychometric Testing is rapidly evolving as a decisive method in psychology with lots of efforts and research by psychometricians and psychologists towards creating efficient and reliable tests. This lead to the evolution of the WAIS (Wechsler Adult Intelligence Scale) and consequently the WAIS-R (WAIS Revised)

WAIS The Wechsler Adult Intelligence Scale IQ tests are the primary clinical instruments used to measure an individual’s intelligence This scale was developed for the average non injured individuals The WAIS-R was developed as an improvement upon the WAIS

WAIS

VERBAL

PERFORMANCE

Verbal

INFORMATIONA series of orally presented questions that tap the examinee’s knowledge of common events, objects, places and people

DIGIT SPAN

A series of orally presented number sequences that the examinee repeats verbatim for Digits Forward and in reverse for Backward

ARITHMETIC

A series of arithmetic problems that the examinee solves mentally and responds to orally

VOCABULARY

A series of orally and visually presented words that the examinee orally defines

COMPREHENSION

A series of orally presented questions that require the examinee to understand and articulate social rules and concepts or solutions to everyday problems

SIMILARITIES

A series of orally presented pairs of words for which the examinee explains the similarity of the common objects or concepts they present

Performance

PICTURE COMPLETION

A set of colour pictures of common objects and settings, each of which is missing an important part thet the examinee must identify

PICTURE ARRANGEMENT

A set of pictures presented in a mixed up order that the examinee rearranges into a logical story sequence

BLOCK DESIGN

A set of modelled or printed two-dimensional geometric patterns that the examinee replicates using two-colour cubes

DIGIT SYMBOL

A series of numbers, each of which is paired with its own corresponding hieroglyphic-like symbol. Using a key, the examinee writes the symbol corresponding to its number

Present scenario in India

• Mental retardation : a common condition.• Survey results: In India around 2% population have

mental retardation.• Problem more acute in children : about 3% of cases

with mental retardation (among all children under 18 years of age in the same village.)

• mental retardation, especially mild mental retardation, more common in rural areas.

• Reasons: poor access to health facilities, under-stimulation, and malnutrition.

Did you know?

Albert Einstein did not speak till he was four years old and could not

read until he was 7.• Current methods of retardation level determination

very subjective.• Evaluation based on direct observation of certain

behaviours.

In direct observation , certain criteria are evaluated . Some of them are:

Literacy Self-Help skills Speech capability Performance of Household chores The response of the candidate compared with

standard responses and a decision is taken.

Problem Definition(Why do it?)

Verdict on Direct Observation ?

Verdict on Direct Observation ?

• Inaccurate

Verdict on Direct Observation ?

• Inaccurate• Not Reliable

A High-Stake Decision

Correct Classification of Retardation Level

Appropriate Treatment for Proper Rehabilitation

A High-Stake Decision

Incorrect Classification of Retardation Level ???

Algorithm

FCM RESULTS

GA

PARAMETERS

FUZZY C-MEANS ALGORITHM

STEP-1

Let N be the cardinality of the set of patterns and K ε [2, N [ be the initial number of clusters respectively.

STEP-2

At step p=0, initialize the matrix U(0) = [uij], which satisfy the following constraint

∑ uij = 1 for i ε { 1, 2, ……. N }

STEP-3

At step p>0, calculate the centroids C(p)

, i.e, the prototype vectors cj

, starting from U(p-1):

Cj= ∑ uij(m).xi/ ∑uij

STEP-4Update the matrix U(p-1), obtaining U(p):

Uij= 1/ ∑(k=1 to K) [ d(xi, cj)/ d(xi,ck)]2/m-1

d(x,y) (Distance Measure) = [ ∑(k=1 to D) wkp

(xk – yk)p ] 1/p

Wk are the weights of subtest which will be optimized by the GA

STEP-5

Verify whether the STOP criterion is satisfied; if it is not, return to point 3.

STOP: || U(p) – U(p-1) || < ε, ε >0 OR S= fixed no. of iterations

Measure of FCM Effectiveness

GENETIC ALGORTIHM

1. It optimizes the weights of the subtests.

2. The objective function depends on the effectiveness and

accuracy of the Fuzzy Clustering ( Xie-Beni Index).

3. This implementation of GA was using Genetic Algorithm

Toolbox, using default options.

4. GA optimization continues till:

a. There is no significant change in the objective function

for 20 sec. OR

b. There is no significant change in the objective function

for 50 generations.

FUZZY CLASSIFIER

• This is the part which actually diagnoses the patient

• Fuzzy Inference System : Mamdani-Type

• The normalized WAIS-R subtest scores are the fuzzy variables.

• For each fuzzy variable the universe of discourse is partitioned by 3

membership functions representing low, medium and high scores.

• The output membership is obtained as a fuzzy set from the aggregation

of the input-scores considering respective weights.

• Final diagnosis is obtained from the defuzzified value of the output fuzzy-

set.

Software

How the Software works Enter the respective subtest scores and then diagnose The data obtained is then passed into the GFCM It then generates the weights that need to be associated with the respective subtest scores This weights’ data along with the user input data is then used by the in-built fuzzy classifier, which classifies the person as either normal, or having borderline mental retardation or complete mental retardation The software shows the output in form of a dialog box

The GFCM uses pre classified data from reliable sources in order to train the system and to determine the weight

The software also has a provision of training the model on user given dataset. This feature of this software enables it to be adopted by users irrespective of their regionability. The average WAIS-R scale is defined differently for different cultural background and the social condition. Because of which, we need to train the software for dataset obtained from that particular region.

Leaving the GUI part, our software is absolutely flexible to put into various uses by just entering the training data for that particular purpose

Our software can also be put to use in a completely different field like assessing a person’s suitability for recruitment in a farm

Why Use This Software?

100% performance in re-substitution testing

Uses standardized test results

Flexibility

Applications

Medical Diagnosis of Retardation Level in Hospitals, Mental-Care Clinics.

School-Admission for Kids; whether some kid requires special attention.

In an extended form, it can be used by job counsellors to scientifically quantify the intelligence level of job-applicants

Future Work

• The test can be improved to include missing data completion feature.

• Collection of more data so that this algorithm can be used for any individual. This would enable this algorithm to become a standard procedure for mental retardation level determination.

•Integration of WISC-R scale along with WAIS-R so that very young children can also be tested accurately.

References

1. “Psychology With Soft-Computing: An integrated approach and its applications”,

Nuovo, Catania, Nuovo, Buono

2. “The Comparability of the WISC-R And WAIS Among 16-Year-Old EMR Children”,

Journal of School Psychology, Nagle, Lazarus

3. “Differential Relationships of Age and Education to WAIS Scores Among Brain-

Damaged and Control Groups”, Reitan, Wolfson

4. “Wechler Subset Patterns of Mentally Retarded Groups: Relationship to g and to

Estimates of Heritability”, Herman H. Spitz

5. “Factor Analysis of the WMS-R and the WAIS”, Nicks, Leonberger, Munz, Goldfader

Acknowledgement

We would like to thank Prof. Barai for his continued support and guidance