Selecting Research Design   The overall plan made by the researcher to get answers to research questions and for testing the hypothesis.   It is the formal plan for the research   Researcher has to choose among presented options.

Aspects of research design  Intervention: whether the researcher want to test effect of specific intervention.  Comparison: if the researcher want to compare between certain phenomena such as: 1.Between groups (males vs. females) 2.Among the same group in different times (now, after 3 months, and after 6 months)

3.Same group with different situations (type II, DM with two types of medications) 4.Based on relative ranking ( levels of organizational commitment and salaries) 5.Comparing with results form other study.

 Controlling for extraneous variables: researcher has to know a head of time what factors he need to control.  Timing of data: the appropriate time and timing  Site and setting: where to find the participants

 Communication with study participants : what information the researcher wants to share with research participants What is the Good Design?  Appropriateness to the research question  Lack of bias: controlling extraneous variables, or any influence that can distort the results.

 Precision: using precise measuring tool and controlling of extraneous variables   Power: ability of research question to detect relationship among variables