6. Inference Methods for Dependent Samples

The method to analyze matched-pairs data is to first combine the pair into one measurement (a new data set!) by calculating the difference between the two data sets. Some examples:

  • If our data set consists of before and after measurements, we subtract the before value from the after value to get a single “difference” measurement.
  • If our data set consists of Twin 1 and Twin 2 measurements, we subtract the Twin 1 value from the Twin 2 value to get a single “difference between twins” measurement.