There are two types of dashes in APA style: en dashes and em dashes. The en dash is shorter, named after the width of the letter n, and the em dash is longer, named after the width of the letter m. Each has distinct uses in writing. For both en dashes and em dashes, do not put any spaces before or after the dashes.
Use an en dash for ranges of numbers (e.g., 3–7) and to connect two terms in an equal relationship (e.g., test–retest). Do not confuse en dashes with hyphens. Although they may look the same, they are usually a little longer than hyphens in most font types such as Times New Roman.
Use em dashes to set off a phrase in a sentence—such as this one—but use them only sparingly.