1. Quantitative and Mixed Research Designs V. Darleen Opfer

2. Design Task A principal/head teacher wants to know whether the provision of professional development will improve the instructional practices of teachers. Design a study for answering her question. In your design, address the following questions: What is the unit of analysis? (Will you focus your study on individual teachers, on subject area, on year levels, on the school as a whole?) What is the unit of analysis? (Will you focus your study on individual teachers, on subject area, on year levels, on the school as a whole?) What is the design chosen for the study? How will you collect your data? What is the design chosen for the study? How will you collect your data? What are your variables? (What are will you be measuring?) What are your variables? (What are will you be measuring?)

3. Conditions for Establishing Cause- Effect Relationships: Covariation Covariation Temporal Precedence Temporal Precedence No Plausible Alternative Explanations No Plausible Alternative Explanations

4. Types of Alternative Explanations History History Testing Testing Instrumentation Instrumentation Regression Regression Mortality Mortality Maturation Maturation Selection Selection Selection by maturation interaction Selection by maturation interaction Ambiguity about causal direction Ambiguity about causal direction Diffusion of treatments Diffusion of treatments Compensatory equalization of treatments Compensatory equalization of treatments Compensatory rivalry Compensatory rivalry

5. Ways to Minimize Threats to Validity: By argument By argument By measurement or observation By measurement or observation By analysis By analysis By preventive action By preventive action By design By design

6. Basic Design Elements Time Time Program(s) or Treatment (s) = X Program(s) or Treatment (s) = X Observation(s) or Measure(s) = O Observation(s) or Measure(s) = O Groups or Individuals = Groups or Individuals = R = Randomly assigned groups

7. An Example: ROXO ROO

8. Expanding a Design: X O Expanding across time Expanding across time O O X O O X O O X O Expanding across programs Expanding across programs O X 1 O O X 2 O Expanding across observations Expanding across observations O 1 O 2 X O 1 O 2 Expanding across groups Expanding across groups R O X O R O O N O O ______________________________ R O X O R O O N O O

10. An Expanded Example The cause-effect relationship The cause-effect relationship X O The comparison on achievement The comparison on achievement O X O O O The expanded design The expanded design C O X O R O X O R O O C O O

11. A Strategy for Design Construction Depict the hypothesized causal relationship Depict the hypothesized causal relationship Identify the possible alternative explanation threats Identify the possible alternative explanation threats Over-expand the basic design by expanding across time, program observations, and groups accounting for as many alternative explanations as possible Over-expand the basic design by expanding across time, program observations, and groups accounting for as many alternative explanations as possible Scale back the design to a manageable plan by considering the effect of eliminating each design component Scale back the design to a manageable plan by considering the effect of eliminating each design component

12. Mixed Designs Mixed Model Research Mixed Model Research –Within-stage mixed model research –Across-stage mixed model research

13. Mixed Designs Mixed Method Research Mixed Method Research

14. The Nature of Good Design Theory-Grounded Theory-Grounded Situational Situational Feasible Feasible Redundant Redundant Efficient Efficient

15. Design Task A principal/head teacher wants to know whether the provision of professional development will improve the instructional practices of teachers. Design a study for answering her question. Reconsider your design, address the following questions: What are your variables? (What are will you be measuring?) What are your variables? (What are will you be measuring?) If you’ve used a mixed method design, is it mixed model or mixed method? Concurrent or sequential? If you’ve used a mixed method design, is it mixed model or mixed method? Concurrent or sequential? What are potential validity/alternative explanation issues with this study? What are potential validity/alternative explanation issues with this study? What are the validity issues accounted for in your approach? And how would you minimize those not accounted for in the design? What are the validity issues accounted for in your approach? And how would you minimize those not accounted for in the design?