Weeks 1-5 Advanced Research Methods

General Linear Model (GLM)

A framework for comparing group means and testing relationships between variables, includes techniques like ANOVA and ANCOVA.

ANOVA

Analysis of Variance; a statistical test used to compare means from three or more groups.

Omnibus Test

A test that checks for overall differences among group means without specifying which groups differ.

F-Ratio

The ratio of model variance to error variance; indicates how much more variance is explained by the model compared to random error.

Between-Groups ANOVA

ANOVA where different participants are in each group, testing means across unrelated groups.

Within-Groups ANOVA

ANOVA measuring the same participants across multiple conditions, testing means related to the same subjects.

Factorial ANOVA

ANOVA that includes two or more independent variables, assessing main effects and interactions.

Mixed ANOVA

Design that combines between-subjects and within-subjects factors to analyze data.

ANCOVA

Analysis of Covariance; extends ANOVA by including covariates that may influence the dependent variable.

Normality

An assumption that data should follow a normal distribution, checked with skewness and kurtosis.

Homogeneity of Variance

An assumption that variances across groups should be similar, tested with Levene’s test.

Independence of Observations

An assumption that observations within each group must be independent.

Effect Size

Quantifies the magnitude of a relationship or difference, providing context beyond p-values.

Cohen’s d

A measure of standardized mean difference; thresholds are small (0.2), medium (0.5), large (0.8).

Correlation

Measures the strength and direction of a relationship between two continuous variables.

Positive Correlation

A relationship where as one variable increases, so does the other.

Negative Correlation

A relationship where as one variable increases, the other decreases.

Post-Hoc Tests

Exploratory tests conducted after ANOVA to examine all group differences, requiring correction for multiple comparisons.

Stratified Sampling

A sampling method that ensures subgroups are proportionally represented in a sample.

Observational Designs

Research designs that examine natural relationships between variables without manipulation.

Experimental Designs

Research designs where one or more independent variables are manipulated to observe effects on dependent variables.

Reliability

The consistency of a measurement, including inter-rater, internal consistency, and test-retest reliability.

Internal Validity

The degree to which changes in the dependent variable are caused by the independent variable, free from confounds.

External Validity

The ability to generalize findings from a study to other populations or settings.

Mixed ANOVA

An approach that combines between-subjects and within-subjects factors into a single analysis.

Method of Least Squares

A method to minimize the sum of squared residuals in regression analysis.

Variance Explained (r²)

The proportion of variance in the dependent variable that can be explained by the independent variable.