Chapter 9: Calculating the Paired- Samples t-Test

longitudinal research

a study in which the same participants are measured at two or more points in time

repeated measures design

the same participants are measured at two or more points in time; also called longitudinal research

within subjects design

the same participants are measured in two different situations or under two different conditions

clinical significance

the size of the effect is large enough to say the independent variable has a meaningful impact on clinical outcome

practical significance

the size of the effect is large enough to say the independent variable has a meaningful impact on the dependent variable (or clinical outcome)

standard error of the difference for difference scores

the standard deviation of the sampling distribution of difference scores (abbrev s(md)) used as the denominator in the paried samples t test equation

individual differences

attributes that vary from case to case

paired samples t test

hypothesis test used to compare the means of two dependent samples; also known as dependent-samples t test, correlated samples t test, related samples t test, matched-pairs t test, within subjects t test, or repeated measures t test

matched pairs

participants are grouped into sets of two based on their being similar on potential confounding variables

pre-post design

participants are measured on the dependent variable before and after an intervention

statistical significance

the observed difference between sample means is large enough to conclude that it represents a difference between population means