End-Of-Chapter (EOC) problems have been part of many physics education studies. Typically, only problems "localized" as relevant to a single chapter were used. This work examines how well this type of problem represents all EOC problems and whether EOC problems found in leading textbooks have changed over the past several decades. To investigate whether EOC problems have connections between chapters, I solved all problems of the E&M; chapters of the most recent edition of a popular introductory level calculus-based textbook and coded the equations used to solve each problem. These results were compared to the first edition of the same text. Also, several relevant problem features were coded for those problems and results were compared for sample chapters across all editions. My findings include two parts. The result of equation usage shows that problems in the E&M; chapters do use equations from both other E&M; chapters and non-E&M; chapters. This out-of-chapter usage increased from the first edition to the last edition. Information about the knowledge structure of E&M; chapters was also revealed. The results of the problem feature study show that most EOC problems have common features but there was an increase of diversity in some of the problem features across editions. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]