Module 8 Psychology for the AP Course (SY 24-25)

Standard Deviation

A measure of variability that describes an average distance of every score from the mean.

Normal Curve

Symmetrical, bell-shaped curve that describes the distribution of many types of data (Normal Distribution) 68% of data points are with in one standard deviation of the mean (34% above, 34% below) 95% of data points are with in two standard deviations of the mean (47.5% above, 47.5% below), 99.7% of data points are with in three standard deviations of the mean (49.85% above, 49.85% below)

Statistical Significance

A statistical statement of how likely it is that an obtained result occurred by chance. The greater the sample size, the more likely we are to find a statistically significant difference between groups.

Descriptive Statistics

numerical data used to measure and describe characteristics of groups. Includes measures of central tendency and measures of variation.

Histogram

a bar graph depicting a frequency distribution

Mode

the most frequently occurring score(s) in a distribution (measure of central tendency)

Median

the middle score in a distribution; half the scores are above it and half are below it (measure of central tendency)

Mean

the arithmetic average of a distribution, obtained by adding the scores and then dividing by the number of scores (measure of central tendency)

Skewed Distribution

a representation of scores that lack symmetry around their average value

Range

the difference between the highest and lowest scores in a distribution

Inferential Statistics

numerical data that allow one to generalize- to infer from sample data the probability of something being true of a population

p-value

The probability level which forms basis for deciding if results are statistically significant (not due to chance).

Central Tendency

The number used to represent the center or middle of a set of data (mean, median, mode)

Percentile Rank

The percentage of scores that are lower than a given score.

Variance

a measure of how much values in a data set differ from the mean

Generalization

the ability to draw conclusions from specific data and to apply them to a broader population