In this paper, I summarise theory and research, highlighting the role of se
lf-defining goals in how individuals react to and try to cope with failure
outcomes. I propose that three factors are fundamental to the understanding
of whether failure stimulates or impairs motivated behaviour: the relevanc
e of failure to a self-definition, the substitutability of tasks in the ser
vice of striving for a self-definition, and a person's commitment to pursui
ng the respective self-definition. Focusing on students' occupationally dir
ected self-definitions, I first review research showing how the interplay a
mong these factors is reflected in varied measures of achievement behaviour
and then discuss practical implications of the theory.