This teaching module offers participants the requisite skills and professional perspective to determine the language dominance of Spanish-language-origin students. Upon completion of this module, participants should be able to (a) identify and describe an example of at least three techniques for determining the language dominance of Spanish-language-origin students, (b) list at least one important disadvantage and one important advantage for each of the three techniques selected, and (c) appropriately administer and interpret the results for each of the selected techniques so as to effectively and efficiently determine the language dominance of Spanish-language-origin students in the primary grades. Participants complete a preassessment test, choose tasks from a list of learning activities, and conclude the module with a postassessment test. (An excerpt from "TESOL Quarterly" entitled "A Method for Determining and Depicting Language Dominance," an article entitled "The Why's and Ways of Testing Bilinguality before Teaching Bilingually," and a bibliography are included.) (PB)