Statistics and ANOVA Concepts

Flashcards created based on key concepts and definitions from statistics and ANOVA lecture notes.

Sum of Squares (SS)

A measure of overall variability, calculated by squaring all numbers in the dataset and summing them up.

Degrees of Freedom (Df)

A count of the units of information regarding residual error in a dataset, allowing for comparisons.

Mean Square (MS)

The average variability per unit of information, calculated as MS = SS/Df.

Standard Deviation (SD)

A measure of the amount of variation or dispersion of a set of values, obtained by taking the square root of the mean square of residuals.

SSCorrectedTotal

Calculated as SSTotal − SSMean, it represents the sum of the squared deviations between each observation and the grand mean.

F-ratio

A test statistic used to determine if there are significant differences between group means, calculated as MSgroup/MSError.

Effect Size (η²)

A measure used to indicate the percentage of variability in the response that can be explained by the model.

Partial η² (η²p)

A measure of the percent of variability explained by a single effect after controlling for variability explained by other factors.

Balance

The presence of equal treatment group sizes in an experiment.

Interaction Effect

Occurs when the effect of one factor on a response variable depends on the level of another factor.

Type I Error

The probability of incorrectly rejecting a true null hypothesis, indicating a difference when none exists.

Bonferroni Correction

A method used to adjust significance levels to control for Type I error when multiple comparisons are made.

Replication

Repeating an experiment to enhance precision of estimates and provide information about errors.

Nuisance Variable

A variable not of direct interest, but must be accounted for to make valid inferences about the parameters of interest.

Nest Factor

When levels of one factor occur with only one level of another factor in a design.

Crossed Factors

When every combination of levels of two factors occurs in a design.

ANOVA

Analysis of Variance, a statistical method to compare means among different groups.

Hypothesis Test

A method used to decide whether there is enough evidence to reject a null hypothesis.

Power of a Test

The probability that the test will correctly reject a false null hypothesis.

Pairwise Comparisons

Comparing all possible pairs of group means to identify differences.