Nonlinear or discontinuous change was analyzed by applying a catastrop
he shift model to data collected on the anxiety levels of Year 12 stud
ents immediately before and immediately after they received offers of
university places. Students' anxiety levels were expected to be subjec
t to rapid change from prearrival of university offers to postarrival
of offers. This process is described, in catastrophe shift terms, as d
iscontinuous or nonlinear change and can indicate a change in state ra
ther than a linear change in degree. Significant differences were reve
aled in anxiety levels from prearrival of offers to postarrival of off
ers for Preference Groups 1, 2, and 3. Bimodality was also revealed, u
sing analysis of variance (ANOVA); however, analysis using cubic regre
ssion indicated that only Preference Groups 1 and 2 demonstrated signi
ficant nonlinear change. These findings suggest that the use of cubic
regression analysis to identify nonlinear change may reveal more compl
ex changes than is indicated by the use of ANOVA alone.