In this paper, the authors report the results of a study that compared differences in the linguistic gains made by native English-speaking students from the United States who were studying Spanish in one of two different contexts of learning. One was a regular university classroom situation in Colorado; the other was a study abroad program in Alicante, Spain. The authors examined the gains students made on a number of linguistic dimensions: oral proficiency, oral fluency, grammar, vocabulary, pronunciation, and communication strategies. In addition, they investigated the relationships between these variables and a variety of background factors, including aspects of language learning readiness. In this paper, the authors review the results, discuss the larger picture that emerges, and speculate on future questions about the effects of the study abroad experience on second language acquisition. They summarize their major findings in terms of three questions regarding differences between Study Abroad and At Home learning contexts. In conclusion, their results indicate that when evaluating the effects study abroad might have on second language learning, it is important to consider more than whether students make greater gains in one environment than in another. (Contains 4 tables and 1 note.)