PSY 2106 Lecture 11: Introduction to Inferential Statistics
8 Nov 2016
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Document Summary
Inferential stats is all about confidence--determining how confident you are that something is true. Inferential statistics is always about the difference between two things. Difference between 1 mean and the number 5. Inferential statistics takes a descriptive statistic (e. g. the difference between 2 means) and assigns a confidence level to indicate how likely there really is a difference in population. By convention, need 95% confidence to generalize to population, i. e. , to call result. But statistical significance confirms that there is something mathematically/statistically significant there. More precisely, degrees of freedom (degrees of freedom is normally the number of people minus one. More precisely, whether hypothesis is directional or nondirectional . Degrees of freedom=df=number of observations that are free to vary. More intuitively, df=number of observations available for determining messiness. It is not until your second observation that you can start gauging messiness around the mean. If you have a score for three people and get a mean of 10.
