1. Department of Educational Psychology
Validate a verbal aptitude test for adolescents: using Item Response Theory (IRT)
RDC Niroshinie
Department of Educational Psychology
Faculty of Education

2. Background of the study
An appropriate methodology to identify verbal aptitudes of the students has not been found so far in Sri Lankan history.
According to carrier counseling theories, adolescents are in pre-occupational stage.
To select subjects, courses, training programmes or career path in accordance with their differential aptitudes.

3. According to Perrone (2016) verbal aptitude is a good predictor for some courses/ subjects related to or jobs such as logic, law, psychology, philosophy
To prevent students from frustrated and depressive mental situations that they face after the G.C.E. O/L examination in selecting A/L subject streams or subjects.
G.C.E O/L failures to identify their verbal aptitude.

4. Key words
Adolescence
Adolescence from the Latin word "adolescere", meaning "to grow up" is a transitional stage of physical and psychological human development that generally occurs during the period from puberty to adulthood.

5. Item Response Theory
IRT models are often referred to as latent trait models.
Item response theory (IRT) is a body of theory describing the application of mathematical models to data from questionnaires and test as a basis for measuring abilities, attitudes, or other variables.
IRT is based on the idea that the probability of a discrete outcome, such as correct response to an item, is a mathematical function of person and item parameters.
The person parameter is called latent trait or ability. Item parameters include difficulty (location), discrimination (slope or correlation).

6. Objectives of the study
Define verbal aptitude
Construct test items to measure verbal aptitude
validate test items
Prepare the final test
Establish validity and reliability of the test

7. Define verbal aptitude
Verbal aptitude is the abilities in word power, analogies and to find commonalities among different concepts and manipulate ideas or statements on an abstract level in a logical way.

8. Item distribution of the test Selecting analogous words (Q1-Q5) (These items were eliminated in the test validation process as they represent language ability rather than verbal aptitude) Selecting odd/different words (Q6-Q12)
Verbal Analogy (Q13-Q20)
Logical Sequence of words (Q21-Q27)
Verbal Reasoning (Q28-Q31)
(Test validation process these items were eliminated as they measure problem solving rather than that of verbal reasoning.)
Cause and Effect (Q32-Q35) Syllogism (Q36-Q40)

9. Research Methodology Population
The students in Grade 11 in Sinhala medium government schools in Western province in Sri Lanka.
Type 3 schools were exempted from the sample.

10. Government schools by functional grade – 2016
Province
District
1 AB 1C
Type 2
Type 3
Total
Western
Colombo 78 79
149
100
406
Gampaha 66
106
187
177
536
Kalutara 49 67
161
140
417
193
252
497
1359
School Census Report, Ministry of Education, 2017.

11. Summary of samples Sample No. of Students Desired Sample
Achieved sample
The first pilot test(Colombo district) 35 30
Second pilot test(Colombo district)
145
120
Third pilot test
712
The final test
1080
1050
Assessment of validity( Cronbach alpha)
Assessment of reliability(Test-retest method)
180
160

12. In terms of IRT, a good item should have several important characteristics
The fit means square index (MNSQ) (Annex 1)
The discrimination index (Annex 2)
Item person map (Annex 3)
Item Characteristic Curve (ICC) (Annex 4)
Distractor Curves (Annex 5)

13. Final Test
20 items
Croanbach α .81
Principal Component Factor Analysis varimax method
(factor loading were above .5)
Test re-test reliability .87

14. References
Anastasi, Anne & Urbina, (2011), Essentials of Psychology Testing, 9thedition, New York: Holt, Rinehart & Winston.
BalladoRonato S., Morales, Romel A. and Ortiz Roger M. (2014), Development and Validation of a Teacher Education Aptitude Test, International Journal of Interdisciplinary Reserch and Innovations, Vol.2, Issue 4, PP ISSn
Barrett, Jim (2015).Career Aptitude and Selection Tests, 2ndeditionKoganPage Limited, p.6-13.
Cochran, L., 2016, Career Counseling: a narrative approach, London, sage publications, 2nd edition p.10-55
Datta, Sumona and Roy, Debdual (2016).Abstract reasoning and Spatial Visualization in Formal Operational Stage, International Journal of Scientific and Research Publications, Volume 5, Issue 10, ISSN
Perrone, Philip A. (2013).A longitudinal study of occupational values in adolescents, Vocational Guidance 71, p

15. Thank you