PSYCH 2300 Lecture Notes - Lecture 10: Internal Validity, Demand Characteristics, Effect Size
30 Mar 2018
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What is the main reason researchers run experiments. A treatment level that serves as inactive control. Placebo effect - expectations lead to results. Not every study needs or can have a control group or placebo group. Doesn"t help you definitively say that the iv caused the dv. Can"t rule out the possibility that expectancy effects explain the results. 2) control and placebo control and treatment. Placebo effect could explain why you might not see a significant difference b/t groups. Often done after treatment vs control and treatment vs placebo experiments. Same fonts, same time, same time of treatment/control activities, same researcher interactions. Iv level 1 = tell kids if they eat all the skittles they"re grounded. Varies systematically w/ iv due to experiment design/procedure. Participants in one iv level systematically differ from participants in another iv level. The way that participants are selected leads to differences or problems. But this may not be effective in small samples.
