ABSTRACT

The Purpose of this study was to develop and standardize a Chemistry achievement test by applying Item response theory. Instrumentation research design was used for the study and the area of study was Umuahia education zone in Abia state. The population of the study comprised of all senior secondary two (SS11) students of 2013/ 2014 academic session in this education zone and a sample of 1035 students were drawn through multi – stage sampling procedure from the population. The instrument used for data collection was Chemistry achievement test (CAT), and to ensure the validity of the instrument, the instrument was subjected to face and content validation by three experts from science education department and one senior chemistry teacher. The reliability index of 0.74 was obtained. The data collected with CAT were analyzed using BILOG – MG computer program. The findings of the study showed that forty eight (48) items of the Chemistry achievement test were difficult and fourteen (14) items discriminated moderately. The findings further revealed that the ability estimates of the male students and female students did not function differentially. Based on the findings, recommendations were made which include that the examination bodies and teachers will be encouraged to adopt IRT in developing test items used in measuring students’ ability in Chemistry.

CHAPTER ONE

INTRODUCTION

Background of the study

Testing has become one of the most important parameters by which a society adjudges the product of her educational system. Testing has always been an important part of the school system that even the habitual absentees normally turn up to school and present themselves for testing on examination days. The essence of testing is to reveal the latent ability of an examinee. Emaikwu (2012) stated that testing has been fully accepted in most modern societies as the most objective method of collecting information for decision making in schools, industries and government establishments. Emaikwu further stated that testing is now used for admission, recruitment, promotion, placement, evaluation, guidance, research and teaching purposes among others. A test according to Nworgu (2003), is a structured situation comprising of set of questions to which an individual is expected to respond independently and each question in the test has a preferred answer. The results of these tests are usually treated in such a way as to provide a quantitative comparison of the performance of the different students.

Based on the level of performance criterion, there are three types of test which are the General mental ability tests, Separate ability test and Achievement test (Nkemakolam,2003).General mental test may also be called “intelligence test”. It is designed to measure a wide range of individual functioning in terms of those mental or intellectual abilities that are useful in almost any aspect of thinking while Separate ability test measures specialized abilities and aptitudes ie they are restricted to the measurement of a limited range of current capacity in a particular area of knowledge such as manipulative ability, mechanical comprehension or verbal ability. According to Nworgu (2003) Achievement test are designed to measure the outcome of the level of accomplishment in a specified programme of instruction in a subject area which a student had undertaken in recent past. Nworgu explained further that achievement test can be classified based on quality into two which are: Teacher-made (classroom) tests and Standardized tests. Teacher –made tests are tests constructed and administered by the classroom teacher for the purpose of measuring the attainment of the objectives by the students. Most tests used in our educational system are of this type.

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