PSY201H5 Lecture Notes - Lecture 4: Medes, Location Test, Standard Deviation
Document Summary
Normal, symmetrical distributions (bell curves: statistically desirable- easy to calculate probabilities. Skewed distributions can be positive or negative: positive skew. Tail to the right is long and flat. Most data are stacked to the left (lower x values) Floor effect: something constraints variable from taking on values below a certain point. Number of kids, number of times in jail, or any low frequency events: negative skew. Tail to the left is long and flat. Most data are stacked to the right (higher x values) Ceiling effect: something prevents variables from taking on values above a certain point. A descriptive statistic that best describes the center of data or the most typical score. 3 central tendencies: mean (average score) All scores affect the mean, because all scores are used to calculate the mean score is the same as mean) Removing scores changes the mean (unless the removed.
