Creating a scale to measure motivation to achieve academically: Linking attitudes and behaviours using Rasch measurement

Motivation to Achieve Academically has been used in many educational and other studies in many countries and the large majority has not used an interval level scale based on a good theoretical model in which the items are linked to behaviour.One, to create an interval level, unidimensional scale of Motivation, with attitude items linked to behaviour items, based on a conceptual model of Motivation, involving Striving for Excellence (Standards, Goals, Tasks, Effort, Values and Ability), Desire to Learn (Interest, Learning from Others and Responsibility for Learning), and Rewards (Extrinsic, Intrinsic and Social). Two, to analyse its psychometric properties using the Extended Logistic Model of Rasch (Andrich, 1988a, 1988b; Rasch, 1980/1960). Three, to investigate the structure and meaning of the scale.The convenience person sample was 239 first-year students selected for three special entry programmes at an Australian university. The stem-item sample was initially 45, reduced to 24, that fitted the measurement model to form a valid and reliable scale.Based on recent literature, a conceptual model of Motivation was devised and items written in line with the model. Data were collected by self-report questionnaire and analysed with the computer program Rasch Unidimensional Measurement Models (RUMM) (Andrich, Lyne, Sheridan, & Luo, 1998). A scale was created in which the Motivation measures were calibrated on the same scale as the item 'difficulties'.Twenty-four Motivation items fitted the model and were 'easier' than their corresponding behaviour items, as conceptualised. They formed an excellent scale in which the proportion of observed variance considered true was 0.93. Items from all aspects of the Motivation model named in the aims above, except Ability and Extrinsic Rewards, fitted the measurement model.The Rasch model and the RUMM computing program were very useful in creating a unidimensional, interval level scale of Motivation to achieve academically, with good psychometric properties.