2 Way anova Flashcards
What is the main purpose of a two-way ANOVA?
To assess the effects of two factors on group means and to determine both individual and combined effects on the dependent variable.
Two-way ANOVA is used in factorial designs with at least two independent variables.
What is the definition of a factorial design?
A study design that includes at least two independent variables (factors).
This design allows for the examination of multiple factors simultaneously.
What is a main effect in the context of two-way ANOVA?
The individual effect of each independent variable on the dependent variable.
Each independent variable has its own main effect.
What does the interaction effect signify in a two-way ANOVA?
The combined effect of two independent variables on the dependent variable.
It assesses whether the effect of one factor depends on the level of another factor.
True or False: The results of a two-way ANOVA indicate which specific groups differ from one another.
False.
Post hoc tests are required to identify specific group differences.
What is the first step in hypothesis testing with a two-way ANOVA?
State the hypotheses for each effect being tested.
This includes null and alternative hypotheses for each main effect and the interaction effect.
How is the decision criteria established in a two-way ANOVA?
By determining the critical F-values for each effect based on degrees of freedom.
Critical values are used to compare against calculated F-values.
What formula is used to calculate the degrees of freedom between groups for the interaction effect?
dfbn = (k1 - 1)(k2 - 1).
Here k1 and k2 represent the number of levels for each independent variable.
What does a significant F-value indicate in hypothesis testing?
That the null hypothesis can be rejected for that effect.
A significant F-value suggests a statistically significant difference exists.
What is the APA format for reporting the results of a two-way ANOVA?
Include F-value, degrees of freedom, and p-value for each effect.
Example: ‘There was a significant main effect of [factor], F(df1, df2) = [F-value], p < 0.05.’
Fill in the blank: A two-way ANOVA requires _______ ratios to be calculated.
multiple F
Specifically, one for each main effect and one for the interaction effect.
What does ‘SS’ stand for in an ANOVA table?
Sum of Squares.
SS measures the variation within and between groups.
True or False: A two-way ANOVA can only be performed using statistical software.
False.
While statistical software is commonly used, it can also be done manually.
Studies that have at least two independent variables (factors) are referred to as having a—————.
factorial design
The ————considers how a single independent variable affects the dependent variable There is one for every independent variable in a study.
main effect
To determine each variable’s main effect, the————— of each main effect (average of the means) is compared.
marginal average
The combined effect of all independent variables (or treatments) on the dependent variable (or outcome) is defined as the————-.
interaction effect
