Two-sample paired T-test is performed when two observations are made on each observational unit. There are situations where completely randomized trials do not provide better responses towards the research questions. The example in Table 7 provides a few examples of such in which the repeated measures on the same observational unit would produce a better result in support of the research questions.

Table 7. Examples for Paired/Matched Paired/Repeated Measure Experiments

Assume that a researcher is interested to compare the drivability of two similar vehicles from two different manufacturers. She hired 15 test drivers and collected the drivability performance data provided in Table 8.

Table 8. Paired T-Test Data

Step 1

Hypothesis

Step 2

Method

Two-sample paired T-Test can be applied as the data comes in pairs for this experimental situation. Analysis can be performed manually using the paired T-Test formula provided Equation 6.

Equation 6

Step 3

Results

In MS Excel, manual analysis using the paired T-Test formula is provided in Table 9.

Table 9. Manual Analysis Results for Paired T-Test Using MS Excel

Analysis using the statistical function in MS excel is provided in Figure 10.

Figure 10. Two Sample Paired T-Test Analysis Results Using MS Excel

Figure 11. Two Sample Paired T-Test Analysis Results Using Minitab