REPORTING AND THESIS WRITING
DETERMINING EXPERIMENTAL AND SAMPLE DESIGNS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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I only.
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II only.
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I and II only.
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II and III only.
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I, II, and III
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Detailed explanation-1: -So, you should keep all the other variables the same (you control them) so that you can see only the effect of the one variable (the independent variable) that you are trying to test. Similar to our example, most experiments have more than one controlled variable.
Detailed explanation-2: -In any experimental design, a researcher will be manipulating one variable, the independent variable, and studying how that affects the dependent variables. A failure to isolate the controlled variables will compromise the internal validity. Most experimental designs measures only one or two variables at a time.
Detailed explanation-3: -Explanation: If more than one variable is changed in an experiment, scientist cannot attribute the changes or differences in the results to one cause. By looking at and changing one variable at a time, the results can be directly attributed to the independent variable.