Development and validation of two soft outcome measures: ‘Disposition to enter HE’ and ‘disposition to study mathematically demanding subjects in HE’

The aim of this paper is to describe and validate the development of two measures constructed to measure AS students disposition (i) to enter HE and (ii) to further study mathematically-demanding subjects, which we regard as potentially significant variables in monitoring or even explaining students progress in to different studies in HE. The items for the scale were constructed on the basis of interview data, and drew on a model of disposition as socially- as well as self- attributed. Drawing on Rasch analyses of pilot and ‘main’ data sets, we find that the two scales each produce healthy one-dimensional fits on what we take to be a ‘strength of commitment to enter HE’ and ‘disposition to study mathematically-demanding subjects further’ respectively. However, as a measurement scale for this sample in this context the former scale suffers from a ceiling effect: our sample are overwhelmingly committed to entering HE (at the early stages of AS level mathematics course anyway). To ‘correct’ for this, we added some harder items to the analysis at a later data point, and found (i) an item that improved separability of the instrument for the higher scorers, and
(ii) a massively misfitting, hard item that is worthy of future research.