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Experimental and quasi-experimental designs

Please help with some examples and information on the following - What are some major differences between experimental and quasi-experimental designs? What different types of manipulations can be used? Any sources would be helpful as this is just one minor part for additional research.

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The key difference between experimental and quasi-experimental designs is the lack of control conditions in the latter.

Let's say I'm trying to study the effects of drug X on neurons' ability to survive. I could easily test this by applying drug X into a well of neurons, stir the media to make sure the drug diffuses across the well and see if I observe any difference in the number of neurons, or the morphology of the neurons in that same well before and after treatment. Keep in mind that although I would have some idea of what drug X might do to the neurons, it does not account for certain actions the experimenter has introduced, such as stirring the media, or adding extra volume ...

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The solution discusses experimental and quasi-experimental designs.