A study was conducted to investigate teacher effectiveness when formative evaluation procedures were implemented in their learning disabilities (LD) resource programs on a regular bases. Procedures included two measurement frequencies (daily or weekly) and two means of determining when to change a student's program (decision rules or teacher judgment). Results indicated that daily measurement was significantly more effective than weekly measurement, and that under certain conditions, decision rules were more effective than teacher judgment. Implications are discussed for the development of useful formative evaluation procedures. (Author)