A fourth study of the impact of classroom assessment practices on students and their learning in the context of the classroom was undertaken by Bangert-Drowns, Kulik, and Kulik (1991), who investigated the effects of frequent classroom testing.
A hyphen (-) is a punctuation mark used to join the separate parts of a compound word. A hyphen is a joiner. A hyphen is used to join the words of a compound adjective (e.g., five-page document), to join the words of compound noun (e.g., cooking-oil), and to join a prefix to a word (e.g., re-examine).
(2) Use hyphens in compound nouns to show they are single entities. In the examples below, the compound nouns are shaded. Often, the non-hyphenated version is acceptable too. However, using a hyphen will make your word easier to identify as a single entity, and it showcases your writing skills.