For example, you could use a Jonckheere-Terpstra test to understand whether test scores, measured on a continuous scale from 0-100, differed based on time spent revising (i.e., your dependent variable would be "test score" and your independent variable would be "revision time", which has four ordinal independent groups: "0-5 hours", "6-10 hours", "11-15 hours" and "16-20 hours"). You expect that median test score increases with increasing hours spent revising. 
Note: The Jonckheere-Terpstra test is similar to the Kruskal-Wallis H test, which can be used to determine if there are statistically significant differences between two or more groups of an independent variable on a continuous or ordinal dependent variable. However, unlike the Jonckheere-Terpstra test, the Kruskal-Wallis H test does not predict how the differences in the scores of the dependent variable will depend on the ordinal nature of the groups of the independent variable. This is explained further in the Assumptions section later.