Which of the following examples shows correct hyphenation?

To determine the correct example of hyphenation, it is essential to understand how hyphens are used in compound adjectives. In this context, the aim is to connect words that function together as a single descriptor before a noun.

The example "Self-report technique" does not require a hyphen because it is not used as a modifier directly before a noun; instead, "self-report" stands alone and clearly describes the technique. However, the other options correctly use hyphens as they describe nouns that are modified by the preceding compound adjectives when placed before them.

For "Randomly-assigned participants," the hyphen connects "randomly" and "assigned," signifying that "randomly" modifies how the participants are assigned. In the case of "Higher-scoring students," the hyphen connects "higher" and "scoring," indicating the specific subset of students being referenced. Both these cases correctly illustrate the use of hyphenation in compound adjectives that precede nouns.

Therefore, although "Self-report technique" demonstrates a proper compound term, it is not in the context where hyphenation is needed. The other examples exhibit the correct usage of hyphenation before nouns, making it evident why they showcase correct hyphenation practices.