Despite the introduction of intervention programs, persons of color and women remain underrepresented in the science workforce. To encourage members of underrepresented groups to pursue careers in science and engineering, programs targeted to pre-college, undergraduate, and graduate students continue to grow. However, understanding of why some succeed and many more fail eludes us. UI seeks to analyze systematically the key factors contributing to and inhibiting success. Such analysis requires research that is carefully designed and executed over more than 1-2 years’ time. It should not be confused with “program evaluation” that produces evidences of effectiveness. Research studies of interventions look across contexts and populations to inform generalizations about causes and effects.