AP Psychology: Types of Statistics for AAQ

Effect Size

A measure of how big or meaningful the difference or_____is between groups; tells you how strong the______is, not the significance.

P-Value

The probability that the results happened by chance; tells you if you can trust the result or not; (___ < .05 = significant, _____ > .05 not significant).

Correlation Coefficiant

A number from –1 to +1 that shows the strength and direction of a relationship between two variables; tells you how related two things are; if 0, no__________at all.

Standard Deviation

A measure of how spread out the scores are from the mean; high SD = scores vary a lot; Low SD = scores are close together.

Percentile Rank

The percentage of scores that fall below a particular score; if you’re in the 90th_________, you scored higher than 90% of people.

Range

The difference between the highest and lowest scores; formula: max – min.

Mode

The most frequent score in a set.

Mean

The average of the scores; add them all up, divide by how many there are.

Median

The middle score when the data are arranged from lowest to highest; in an even set, arrange from lowest to highest, add up the two middle numbers, and divide them by 2.