Umalusi Newslette

Improving assessment practices through Item Response Measurement

By Nthabeleng Lepota

Assessment is a critical part of the teaching and learning process. It is, therefore, very important for all stakeholders with an assessment interest to reflect on and evaluate the effectiveness of teaching, learning and assessment through measuring candidate responses. As a result, there is a need for a reliable and valid approach that can evaluate ability levels in learners’ responses to items and tasks. Application of the Item Response Theory (IRT) could assist in determining learners’ ability. IRT is a mathematical model used to provide accurate measurement results about candidate ability, growth and achievement.

The most critical insight we can gain from IRT is that a candidate’s response to a set of items of various demands can tell us about their level of ability to respond to the items. For example, mathematical problems set in an examination can tell us, broadly, about a candidate’s mathematical ability. Additionally, IRT can be used to evaluate the characteristics of items set in an examination. The properties refer to how difficult an item is and how well it discriminates between candidates of lower and higher abilities. With IRT, we can also determine if a candidate scored an item correct simply by chance, through guessing.

MAKOYA NEWSLETTER September 2020

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