Threats to the validity of the Title I Evaluation and Reporting System are covered in two parts: an annotated bibliography of reports concerned with technical issues, and a discussion of threats to validity--from the reporting system in general and from each model in particular. Threats common to all three evaluation models are reported: instrumentation effects involving scaling as related to internal validity; statistical power; multiple comparisons and the error rate problem; test reliability as related to statistical conclusion validity; aptitude--treatment interactions; inadequate preoperational explication of the treatment construct as related to construct validity of cause; and inadequate preoperational definition of effect construct and mono-operational bias as related to construct validity of effects. Specific problems associated with Model A, Model B, and Model C are reviewed, and suggestions are made for overcoming these problems. (MH)