PSYCH 2317 Ch. 12 MindTap

post hoc test

additional hypothesis test done after an ANOVA to determine whether mean differences are significant

distribution of F-ratios

all possible F values that can be obtained when the null hypothesis is true

mean square

average of the squared deviations

treatment effect

cause of differences between treatments

pairwise comparison

comparison of individual treatments two at a time

total

entire set of scores

k-1

formula for between-treatments degrees of freedom

SS total- SS within

formula for between-treatments sum of squares

N-1

formula for total degrees of freedom

EX^2-G^2/N

formula for total sum of squares

E(n-1)=Edf in each treatment

formula for within-treatments degrees of freedom

ESS inside each treatment

formula for within-treatments sum of squares

level

individual condition or value that makes up a variable

error term

measure of the variance caused by random, unsystematic differences

eta squared

percentage of variance accounted for by the treatment effect in published reports of ANOVA results

two-factor design or a factorial design

study that combines two variables

single-factor design

study that has only one independent variable

F-ratio

comparison between how much difference exists versus how big the differences are between treatment conditions

Tukey's HSD test

computation of single value that determines the minimum difference between treatment means necessary for significance

ANOVA summary table

diagram showing the source of variability

analysis of variance (ANOVA)

hypothesis-testing procedure used to evaluate mean differences between two or more treatments or populations

between-treatments variance

measure of how much difference exists between treatment conditions

within-treatments variance

measure of how much difference exists inside each treatment condition

Scheffé test

method using an F-ratio to evaluate the significance of the difference between two treatment conditions

testwise alpha level

risk of a Type I error for an individual hypothesis test

between-treatments

term referring to differences from one condition to another

within-treatments

term referring to differences that exist inside the individual conditions

experimentwise alpha level

total probability of a Type I error accumulated from all individual tests in the experiment

factor

variable that designates the groups being compared