Assignment of measurement period by an "expert" computer program

This paper discusses an attempt to reassign physical therapy evaluations to meaningful time periods based on recovery after surgery for hip fracture. The time of each evaluation post surgery is recorded in days and months by the physical therapist doing the evaluation. At the same time, the physical therapist assigns a name to the time period 'pre-strength training', 'post-strength training', '6 month etc'. However the patient and other outside factors affect the actual time that elapses between evaluations. When the study was completed, the early examination of the data, revealed that the period assignments had a wide spread over time. We constructed an expert program, to try to adjust the period name assignments using the actual time post-surgery as well as the time relationship to the strength training.