This research abstract describes my proposed doctorial work within the fi eld of software project cost and effort estimation. My work focuses on assessment of uncertainty of software development cost or effort estimates. In particular, the work focuses on to which degree this assessment is a skill that can be improved with better training. Work completed includes one small scale experiment with student participants. A followup, larger, experiment with professional software developers is currently in progress. Studies targeted towards better understanding of the mental processes of development of work effort estimates and uncertainty assessments will be the next step. This work aims at the development of effective training processes of estimation and uncertainty assessment skills. Through the METRICS05 dissertation forum I hope to receive feedback on the viability and relevance of the proposed work within the software cost and effort estimation field.