By using a taxonomy of instructional strategy variables, an Instructional Strategy Diagnostic Profile (ISDP) was developed which can be used either to determine a judged index of instructional effectiveness for a previously designed instructional product or to guide the design and development of a new instructional product. Existing experimental research was examined to determine the empirical base underlying ISDP propositions relating student performance to parameter values on instructional strategy taxonomy variables. The following propositions or partial propositions were supported: (1) a segment of instruction should include all three of the primary presentation forms: rule, example, and practice; (2) the rule should be stated in other than verbal form or should be elaborated via an algorithm; (3) example displays should be elaborated via devices which focus the student's attention on the relevant attributes, and/or practice displays should provide explanatory feedback; (4) example or practice displays used alone would include nonexamples matched to examples on the basis of variable attributes; and (5) example and practice displays should include a divergent set of instances which range in difficulty. There is considerable empirical research support for most of the propositions underlying the ISDP, and it seems reasonable to predict that a given instructional package judged to have a high ISDP index should provide effective instruction. (Author/LBH)