On a regular spring time a lot of tulip flower fields outside the Keukenhof are headed (taking the flower off) on the 30th of April or within a couple of days after it. If you want to see the flower fields as well make sure that you visit before this date!
In factorial designs, a factor is a major independent variable. In this example we have two factors: time in instruction and setting. A level is a subdivision of a factor. In this example, time in instruction has two levels and setting has two levels. Sometimes we depict a factorial design with a numbering notation.
Once you have determined that the design uses two or more samples or groups, then you must determine how many samples or groups are in the design. Studies that are limited to two groups use either the chi-square statistic, Mann-Whitney U, Wilcoxon T, independent means t test, or the dependent means t test.