Correlations & Statisitcs

Correlation

a measure of how two variables relate to each other

Correlation Coefficient ( r )

A number from –1 to +1 showing the strength/direction of a correlation.

Scatterplot

A graph showing the relationship between two variables.

Positive correlation

Two variables increase or decrease together.

Negative correlation

One variable increases while the other decreases.

Illusory correlation

Thinking two things are related when they’re actually not.

Mean

average score

Median

middle score

Mode

most frequent score

Measures of central tendency

Describe the average (mean, median, mode).

Measures of variability

Describe how spread out data is (range, standard deviation).

Range

Highest minus lowest score.

Standard deviation

A measure of how much scores vary around the mean.

Normal curve

A bell-shaped distribution where most scores are near the average.

Inferential staistics

Determine whether results can be generalized to a population.

Descriptive statistics

Summarize data but don’t generalize it.

Probability

Likelihood an event happens.

Statistical significance

The result is unlikely due to chance (usually p < .05). more than 0.5 is significant