As part of an ongoing project to reform the introductory algebra-based physics courses at George Washington University, we are developing a taxonomy of introductory physics problems (TIPP) that establishes a connection between the physics problems, the type of physics knowledge they involve and the cognitive processes they develop in students. This taxonomy will provide, besides an algorithm for classifying physics problems, an organized and relatively easy-to-use database of physics problems that contains the majority of already created text-based and research-based types of problems. In addition, this taxonomy will reveal the kinds of physics problems that are still lacking and that are found to be necessary to enhance students' cognitive development.  For this reason, we expect it to be a valuable teaching resource for physics instructors which will enable them to select the problems used in their curricular materials based on the specifics of their students' cognition and the learning objectives they want to achieve in their class. This organization scheme will also provide a framework for creating physics-related assessments with a cognitive component.