Describing Scores on a Single Variable

** With
pictures: **

frequency distribution; bar chart (histogram), line graph, bar graph

With numbers:

1. central tendency -mean; median; mode

2. variability/variation/dispersion —

range(sensitive to outliers)

sum of squares

varianceVariance is the basis for inferential statistics such ast-test, F-test, and ANOVA.

standard deviation(original units)(used to standardize scores)

3. skew (kurtosis)...

standard(ized) scores -m = 0, s = 1 (z-scores)

With pictures: scatterplot

With numbers:

association —

correlation —Pearson coefficient,r

variance accounted for

regression line

*Correlation is the basis for inferential
statistics such as multiple regression.*