longitudinal designs, which allow researchers to establish temporal precedence in their data;
multiple-regression analyses, which help researchers rule out certain third-variable explanations;
the “pattern and parsimony” approach, in which the results of a variety of correlational studies all
support a single, causal theory.
In the three techniques, as in all correlational studies, the variables are measured—that is, none are
manipulated.
INVOLVES MORE THAN TWO MEASURED VARIABLES
multiphase iterative design - Mixed-methods design that includes three or more phases; earlier phases
inform conceptualization and implementation of subsequent phases.
