GAS Reliability Data N=79

For over 50 years, Goal Attainment Scaling (GAS) has been a useful but controversial tool in evaluating outcomes for individuals undergoing rehabilitation. Despite measuring meaningful goals, it has been criticised in the literature for its unstandardised and imprecise GAS scale construction that results in questionable reliability and validity. The aim of the current study was to assess and compare the inter-user reliability and temporal stability of the construction of GAS scales using a conventional (Flexible) and modified (Structured) approach. First-year university psychology students (N = 79) constructed GAS scales for six separate goal-setting scenarios based on the GAS condition (Structured or Flexible) they were randomly assigned to, and they were invited to repeat GAS scale construction for the same scenarios two weeks later. GAS scale median and range scores were compared across raters within each group at Time 1 to assess inter-user reliability and across Time 1 and Time 2 to assess temporal stability. Structured GAS demonstrated higher inter-user reliability than Flexible GAS for both the median (κ = 0.28; κ = 0.19) and range scores (κ = 0.30; κ = 0.05). Structured GAS also demonstrated higher temporal stability across a 2-week period, with greater overall Kappa values for the median and range scores. In conclusion, Structured GAS demonstrated greater inter-user reliability and temporal stability than Flexible GAS among novice GAS users.