Research has shown the importance of subject-specific concepts for understanding the subject and how textbooks have a decisive role in this. This study aims to investigate and compare the occurrence and use of subject-specific concepts in three textbooks that deal with the subject of social studies for grades 4-6 within chapters Politics & Law and Rights. The goal is to identify how much of the teaching material uses subject-specific concepts and how they are conveyed, but also whether they make them understandable to the reader. To help investigate this, three questions have been designed: 

1.     Which subject-specific concepts appear in each textbook?

2.     With what frequency do subject-specific concepts occur?

3.     How are the subject-specific concepts meaning explained in the textbooks for the students?

Järborg’s vocabulary categories were used as an analysis model in this study. To answer these questions, a quantitative content analysis and a qualitative text analysis were made. They were applied to three different middle school textbooks. The results showed that all three textbooks had subject-specific concepts approaches in the topic of politics & law and rights. It also revealed that all of the three textbooks had a few concepts in common, some were common just in two textbooks and other appeared in only one of them. Textbook 1 contained a total of 33 subject-specific concepts, textbook 2 contained a total of 32 subject-specific concepts, and textbook 3 contained 35 subject-specific concepts within the two selected chapters. The study also showed that all three textbooks use different methods that in this study were divided into four categories. More specifically, the result showed that the textbooks applied explicit definitions more.