APA 2180 Lecture Notes - Lecture 17: Spurious Relationship, Partial Correlation, Effect Size
20 Mar 2019
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Spurious correlation: relationship between two variables is due to the common influence of another variable. Residual scores difference between predicted and actual scores. Partial correlation: determines relationship between 2 variables, with the variance of a 3rd variable removed, partialed out or held constant (controlled for) Power defines the strength of the study. Want to know effort cost, patient involvement. Want to know if the study will be successful. Low power means that means you might miss important information. As alpha decreases beta increases (inversely related to each other) Effect size is simply a way of quantifying the size of the difference between two groups. If you have a conservative alpha that means you need more people in the study to find a statistical difference. Will give chart, but has to find sample size and effect size. All of these means that you need a lot of people for the study.
