For the hypothetical data contained in Table 13.2, eight participants were measured at three occasions. The question of interest is: "Is there a population mean difference between across Time 1, Time 2, and Time 3 measurement occasions?" Table 13.2 presents hypothetical data for a three-level design. The null hypothesis to be tested is that the population means of scores at all three time points are equal to each.
References
Maxwell, S. E., Delaney, H. D., \& Kelley, K. (2018). Designing experiments and analyzing data:
A model comparison perspective (3rd ed.). New York, NY: Routledge.