12 - - Controls for major threats to internal validity- Two...

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1.) Hawthorne effects: behavioral changes due to the fact that they know they are being studied. - increased light improved participants' performance, dimmed lights also improved performance. Finding: attention is what improved performance, not lights. Random sampling: Choose sample, make sure every person in the population has an equal chance of being selected. 2.) Characteristic of a True Experiment - Random assignment - Pre- and post-testing - At least two levels of IV (one can be 0)
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Unformatted text preview: - Controls for major threats to internal validity- Two alternative theoretical explanations (H1 & H0) (place 1 & 0 below H). 3.) Selecting subjects: Probability sampling is best, but . ..- Randomizing- Increases confidence that small samples are representative- Why? Because randomization. ..randomizes everything- Matching- What attributes you match on depends on your RQ- Randomization s better- most statistics assume it....
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This note was uploaded on 10/27/2008 for the course COMM 301 taught by Professor Matsaganis during the Fall '08 term at USC.

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