|Title||Selection of Effort Estimation Strategies|
|Afilliation||Software Engineering, Software Engineering|
|Publication Type||Journal Article|
|Year of Publication||2010|
|Journal||Journal of Systems and Software|
We currently know little about the factors that motivate the selection and change of estimation strategy in judgment-based effort estimation context. A better understanding of these issues may lead to more accurate judgment-based effort estimates and motivates the four experiments reported in this paper. The experiments' two main results are the identification of the importance of “estimation surprises” (large estimation errors) to motivate estimation strategy change and the large individual variation in the initial choice of estimation strategy. The individual variation seems not only to be a result of differences in previous experiences, but also a result of differences in the mental “accessibility” of the strategies. We found, for example, that the use of a strategy was increased when we instructed a developer to use the same type of strategy on unrelated tasks immediately before. The laboratory contexts of the studies means that the results should be interpreted as a first step towards more knowledge about expert estimation strategies and that there is a strong need for more studies, preferably in field situations, before recommending actions on the basis of the findings.