Constructed-response formats are desired for measuring complex and dynamic response processes which require the examinee to understand the structures of problems and micro-level cognitive tasks. These micro- level tasks and their organized structures are usually unobservable. This study shows that elementary graph theory is useful for organizing these micro-level tasks and for exploring their properties and relations. Moreover, this approach enables us to better understand macro-level performances on test items. Then, an attempt to develop a general theory of item construction is described briefly and illustrated with the domains of fraction addition problems and adult literacy. Psychometric models appropriate for various scoring rubrics are discussed. (59pp.)