Review: Core Concepts, Chs. 1-5

Frequency distribution: Shows the relative frequency of different scores on a variable. Can be graphically represented as scores "piled up" along a number line of values.

Variables: Discrete or continuous, play "dependent" or "independent" roles . Can be measured on different scales.

Central tendency: For inferential stats, the mean, which summarizes information from ALL scores, is the most important. The location of the mean is affected by skew.

Variability: Most important are variance and standard deviation. Both reflect information from ALL scores.

Z-scores: Show the location of individual scores in a frequency distribution. Used to "standardize" scores.

Core Skills, Chs. 1-5

1. Organize a set of scores into a frequency distribution table or histogram

2. Identify the key features of a distribution by looking at a histogram

3. Calculate the mean

4. Calculate the variance and standard deviation

5. Transform X scores into Z scores and vice versa