Applying Item Response Modelling to Confirm the Underlying Construct of a New Process Instrument in Gymnastics

Three cohorts were observed performing a gymnastic locomotor skill – the forward roll. These groups included: children (n=48) aged between 6 years and 15 years; young adults (n=24) aged between 18 years and 22 years; and, older adults (n=45)aged between 28 years and 42 years. Qualitative analysis of visually recorded data resulted in the forward roll being categorised into three sequences, the 'beginning','middle' and 'end'. For each sequence a number of 'indicators' were identified. Each 'indicator' was further sub-divided into a number of 'descriptors'. These 'descriptors' were hierarchically ranked and using the 'Quest' (ACER) statistical package; a Rasch analysis was employed to determine whether the 'descriptors' confirmed the underlying construct. The application of the Rasch model was confirmatory for identifying the structure of a range of quality movement performances.