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Classical experimental design relies on researcher's ability to control the settingManipulation of at least 1 Ind. variableRandom assignment of subjects to groupsRandom assignment of Ind. Variable to group(s)Exposure of experimental group to treatment in isolationThis not very practical in so
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1. Quasi-Experimental DesignsNonequivalent Comparison Groups Chad Reed
March 12, 2008
2. Classical experimental design relies on researcher's ability to control the setting
Manipulation of at least 1 Ind. variable
Random assignment of subjects to groups
Random assignment of Ind. Variable to group(s)
Exposure of experimental group to treatment in isolation
This not very practical in social research
Introduction
3. When all classic requirements can’t be met Quasi-Experimental Designs (QEDSs) will be used
As many requirements will be used as possible, but other measures are adopted to offset threats to Internal Validity
Key Component
Groups are Not Randomly Assigned
Step Away from the Classic Model
4. Structured much like pretest-posttest experiments but lack the randomized designs How then are Participants Selected to Each Group? Self Selection Administrator Assignment Different treatments at different sites Nonequivalent Groups