EPSY 363 Lecture Notes - Lecture 9: Normal Distribution, Standard Deviation, Statistical Significance

• School: UIC
• Department: Educational Psychology
• Course: EPSY 363
• Professor: Mikayla Strasser

Document Summary

When you know a mean and a standard deviation, you"ll know where most of a group falls (68% fall within 1 unit of standard deviation from the mean) The purpose is to determine the probability (p) that findings are due to an error in sampling. A low p-value means that the findings are not due to sampling error and are most likely due to the treatment. Statistical significance means there is a low probability that the results are due to sampling error. Statistical does not mean that the findings are necessarily important. There are some statistical tests that will give you significant statistics but you can"t really interpret anything from them. Alpha is the significance level of a statistical test. We select a value for alpha based on the level of confidence you want to have that the test will avoid a false positive (aka type i error).