This paper describes in some detail Siegfreid's Process Mapping Model for describing human performance. The model's application to task analysis and the advantages of using it when constructing assessment strategies and instruments are discussed. Examples of the model's use in building portfolios, behavioral rating scales, and skill demonstration packages are set forth. Such skill demonstration packages can, when properly constructed and organized, identify those individuals whom one can conclude are able to perform various activities related to a job. They will not, however, predict the extent to which these individuals will perform adequately on the job. The authors suspect that skill demonstration packages may be most useful in diagnosing areas in which a given counselor needs to improve skill, as opposed to being used in predicting a counselor's level of effectiveness. (Author)