This volume comprises a collection of papers and transcribed discussions from a conference held in Tempe, Arizona in June 1993. The contents represent a wide range of contributions, from the empirical to the theoretical, and include methods for measuring developmental instability across a variety of taxa and traits. Contrasting views on how to assess developmental instability are included, and the relationship of instability to genotypic factors, environmental factors and the action of natural and sexual selection is addressed. Readers should derive a working knowledge of the best way to assess developmental instability and should be able to design future work in an authoritative way.