Experimental Design

Title: Also know as problem statement. Does it identify both the Independent Variable and the Dependent Variable? Example: The Effect of (the independent variable) on (the dependent variable).

Hypothesis: Does the hypothesis clearly state how you think changing the Independent Variable will affect the Dependent Variable? Example: If the(independent variable) is (describe how you changed it), then the (dependent variable) will (describe the effect).

Independent Variable: The independent variable is the variable that is changed on purpose. Is there just one independent variable? Is it well defined?

Levels of Independent Variable: Are the levels of the Independent variable clearly stated? Are there enough levels of the independent variable being tested? Are there too many?

Controls: The level that you compare all others to. Is there a control? Is it clearly stated?

Trials: The number of times that you repeat the experiment. Are there repeated trials? Are there enough of them?

Dependent Variable: The response that occurs from the changes made to the IV. Is the DV clearly identified? Is the DV operationally defined? Operationally defined means that the investigator very clearly stated how the response would be measured or described.

Dependent Variable: Measurements need to be either Qualitative or Quantitative. Qualitative – observations include verbal descriptions or measurements with non-standard scale. Quantitative – observations include measurements with standard scale.

Constants: The things in the experiment that stay the same throughout. Are the constants clearly identified and described?

Complexity: Was the experiment creative? Was it an appropriate level of complexity? (judgment call)

Experimental Design Diagram Title: Hypothesis: Independent Variable (Control) Levels of IV Including control Repeated Trials # of times each of the levels of IV was tested. Dependent Variable: Constants:

Four Question Strategy: Q1: What materials are readily available for conducting experiments on (…)? Q2: How do (…) act? Q3: How can I change the set of (…) materials to affect the action? Q4: How can I measure or describe the response of (…) to the change?