Personal journeys, professional paths: persistence in navigating the crossroads of a research career.

Persistence in a research career can be readily understood within the trainee models that have emerged from undergraduate and graduate instruction. These models offer a common language for discussing training processes, serve as guides for assessing trainee needs, promise to render training programs that are more comprehensive and attentive than are current programs to the factors that contribute to academic and scientific persistence, and enable us to measure with greater precision, internal consistency, and generalizability the elements that logically belong in research career development programs.