This paper addresses the question of whether introductory students are learning the essential concepts of sociology. A study of 18 introductory sociology textbooks, dated from 1973 through 1977, indicates that these basic concepts are not clearly and intelligibly presented. Although over 1500 concepts were included in 18 glossaries, only one concept, "culture," was listed by all 18 books. Problems result from a lack of agreement as to which concepts are the most basic and from the proliferation of terms included in textbooks. In addition, many textbooks fail to distinguish between "key terms" and "concepts." Suggestions are that teachers attend more closely to glossaries of textbooks and that they exert pressure on authors, publishers, and representatives to insure that the"professional vocabulary" is more consistent. Lists of textbooks studied and of the most frequently used concepts are included in appendices. (KC)