Deciding whether a study will compare different groups of individuals or examine changes within the same group of individuals involves a decision about the research .

Deciding whether a study will compare different groups of individuals or examine changes within the same group of individuals involves a decision about the research design.

Explanation:

Behavioral research studies about patterns and their variables of individual and social behavior of a person with response to stimuli (internal or external)

A research design essentially is the blueprint of the research that integrates and interlinks various research components like evidence and data collection, measurements undertaken, analysis and the interpretations made in a coherent, logical and comprehensive way.

Decision about the type of comparison group in group experimental researches is taken during research design to decide about how the comparison should be made to obtain the correct results. It can be compared with an individual to a group, or a control group against an experimental group.

The pattern changes in each group is studied based on the independent  variables which changes in the experimental group and is fixed or constant in a control group.

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