PY 101 Lecture Notes - Lecture 3: Central Tendency, Descriptive Statistics, Standard Deviation

• School: University of Alabama
• Department: Psychology
• Course: PY 101
• Professor: Natalie Dautovich

Document Summary

Reliability- stability and consistency of a measure over time. Descriptive statistics- used to describe the data (the scores for each participant on the variables) in a concise way. Measures of central tendency- the value around which scores cluster; the typical score in a data set. Designed to summarize a set of data w/ a single number. Mean- numerical average for a distribution of scores. Add up the values of all the scores and divide by the number of scores. The most commonly used measure of central tendency. Caution- the mean, because it uses all scores in its computation, can be distorted by extremely high or extremely low scores (outliers in the data) Median- the score that is positioned in the middle of the distribution of scores when scores are listed from lowest to highest. If there is an odd number of scores, the medium is the middle score.