Inferential statistics
Tools used to infer conclusions beyond the sample data.
Inferential Statistics
The threshold for deciding if a result is statistically significant (commonly .05).
Significance Level (α)
Compares means between two different groups.
Independent Samples t-test
Tests relationships between categorical variables.
Chi Square Test
As one variable increases, so does the other.
Positive Relationship
A process for determining whether a hypothesis is supported or rejected.
NHST
The number of values in a calculation that are free to vary.
Degrees of Freedom
Compares means from the same group at different times.
Paired Samples t-test
Measures the direction and strength of a relationship.
Correlation
As one variable increases, the other decreases.
Negative Relationship
A testable statement predicting a relationship or difference.
hYPOTHESIS
Incorrectly rejecting a true null hypothesis (false positive).
Type I Error
Predicts a result in one direction only
One tailed test
A false relationship caused by a third variable
Spurious Correlation
How closely two variables are related.
Strength of Correlation
The assumption that there is no effect or relationship.
Null Hypothesis
Failing to reject a false null hypothesis (false negative).
Type II Error
Tests for the possibility of an effect in both directions.
Two-tailed Test
An outside variable that may influence both variables being studied.
Third Variable
A formula that predicts a dependent variable.
Regression Equation
The probability the observed result happened by chance.
p-value
Compares means across 3+ groups.
ANOVA
Predicts the value of a dependent variable from one or more independent variables.
Regression
A line that best represents the data in a scatterplot.
Line of Best Fit