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

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.

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.

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.

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).

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

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.

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)

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.

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.

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

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)

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

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. 129-133 ISSn 2348-1226. 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 2250-3153. Perrone, Philip A. (2013).A longitudinal study of occupational values in adolescents, Vocational Guidance 71, p. 116-123

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