T for 2 (Paired Sample)

Single Sample T-Test

• One set of participants

Independent t-test

• Two sets of participants

Paired Samples t-test

• One set of participants measured twice

Paired Sample T-test

• Within-subjects design

  • Research design in which each participants provides at least two responses to be compared

Repeated Measure Designs

• Testing the same sample more than once, possily over time

Matched Samples Design

• Comparing pairs of people matched on some attribute

T-test for two paired samples

• Each observation in one sample is paired with a single observation in the other sample

• Compairing sampling distribution of the sample mean of the difference scores to the sampling distribution of the hypothetical mean of the difference scores.

Difference Score

• The difference between a pair of scores in two matched samples

Matched Samples

• Pros

  • Less Variability

• Cons

  • Less external validity

  • effect of repeated measure

  • fewer degrees of freedom than independent samples t-test