Concept and implementation of a two-stage coding scheme for the development of computer-based testing (CBT)-items in traditional test software

Abstract

Computer-based testing (CBT) is gaining importance for studies addressing the diagnosis of competencies, because it is possible to simulate authentic action situations and may reduce the effort of analyzing the data. This benefit is most important for the phase of item design. In this phase of assessment construction, the pattern of answers of a sample is used to draw conclusions on the functionality of the items. Currently, there are no standards for the encodement of items which consider the specifications of CBT-instruments. These specifications are, for example, the a posteriori non-variability of the coding, a lack of information when using conventional test scores and the need of standardization of different formats of items. Taking these specifications into consideration, this paper proposes and discusses a two-stage coding systematization for CBT-items. For this, a distinction between item-coding and answer-coding was done. The coding is discussed for single-section and multi-section formats as well as dichotomous and polytomous answer modes. Therefore, this paper is for users of CBT-instruments who want to achieve the optimal information value of their test results with efficient coding.