Using adaptive comparative judgement to obtain a highly reliable rank order in summative assessment
Adaptive Comparative Judgment (ACJ) offers an alternative to marking, especially for performance assessments for which achievement can be difficult to describe in mark schemes. The ACJ system uses a web-browser to deliver pairs of candidates’ work to judges. The judges apply their subject expertise to select which of the two sets of work is better in terms of meeting appropriate educational objectives.
A quality parameter is estimated for each piece of candidates’ work using the Rasch logistic model to analyse the judges’ decisions. Placing the pieces of work on a measurement scale gives them a rank order. The adaptive nature of ACJ lies in the pairing of essays for each judge. The selection of essays is based on a maximum distance between the quality parameter estimates, allowing useful information to be gained from each paired comparison.
This paper reports a study in which ACJ was used to rank order a random sample of 564 essays on a topic in physical geography based on the judgements of a group of 23 teachers and examiners. The reliability of the rank order was 0.97. Evidence is presented for the need for judges to be teaching at the same qualification level as they are judging at. There is a discussion of the factors that need to be addressed before implementing ACJ in summative assessment.