People need concepts to be able to think and express what they think. Thanks to concepts, cognitive structures can be created, events and facts can be making sense and interpreted. In addition, concepts are used to make sense of a new situation and relate it to previous information. While concepts enable the individual to understand the physical and social world and communicate meaningfully (Senemoğlu, 1998), on the other hand concepts combine and organize similar pieces of information, helping us place them in our memory in categories. And this makes it easier both to learn new concepts and to remember learned concepts (Yel, 2012). If things, objects, events, or facts were not grouped considering their common characteristics, it would be necessary to learn each element separately and it would be quite difficult to communicate (Çeliköz, 1998). Therefore, it will be difficult to communicate in a world without using concepts and life will become much more complex. In order to achieve the goals determined within the scope of the social studies course, the concepts in the program must be understood by the students. Because, like everyone, students can think and express their thoughts through concepts. Various methods are used in order to teach of concepts and eliminate the misconceptions in education. Semantic Feature Analysis (SFA), Concept Maps, Concept Crosswords, Conceptual Change Texts, Concept Networks and Concept Cartoons is some of these methods (Alkış, 2014; Demirkaya and Karacan, 2016, s.40; Dündar, 2011). Another method used to reveal how concepts are understood and misconceptions is the Word Association Tests. Thanks to word association tests; the cognitive structures of people, the connection between these structures and the information networks existing in the mind can be revealed. In addition, the concepts in long-term memory, connections between concepts and the quality of these connections can also be revealed through word association tests (Bahar & Özatlı, 2003; Ercan, Taşdere & Ercan, 2010; Karakuş, 2019). In the word association test method, the student is given a keyword. The student presents the words evoked by the given keyword in his mind as answer. In this process, it is important that the student gives the answer within a certain period of time, such as 30 seconds. It is assumed that the response of the individual by calling from her long-term memory for any concept reveals the relationships between the concepts in the cognitive structure of the person and shows the semantic affinity. There are various studies in the field of social studies education related to the word association test method (Aydemir, 2014; Ay ve Tokcan, 2019; Deveci, Köse ve Bayır, 2014; Işıklı, Taşdere ve Göz, 2011; Karakuş, 2019; Öztürk ve Yılmaz Özcan, 2017; Şimşek, 2013; Tokcan, Yiter, Oğuz, Kesmeci ve Karakuş, 2015; Tokcan, 2016; Tokcan ve Topkaya, 2016; Tokcan ve Topkaya, 2018; Tokcan ve Yiter, 2017; Ünal ve Er, 2017). These studies mostly were prepared to reveal how some concepts related to social studies course (Atatürk's principles, social studies, social sciences, natural disaster, Middle East etc.) are perceived by students and prospective teachers and misconceptions about these concepts. The aim of this study is to reveal the cognitive structures of prospective social studies teachers related to the concepts of Ottoman and Conquest through the word association test. The study was prepared in accordance with the qualitative research method and was designed according to the case study pattern. The study group consisted of 124 prospective social studies teachers studying at a state university’s faculty of education. The Word Association Test prepared by the researchers was used in the study as a data collection tool. Ottoman and Conquest key concepts were chosen to create the test. Before starting the test, participants were made explanations about the word association test and were asked to write the first five concepts that the key concept brought to their minds within 30 seconds while the test was being applied. The 30-second duration was used on some previous studies and successful results were obtained (Keskin & Örgün, 2015, p.33; Polat, 2013, p.104). The word association test prepared for the purpose was distributed to prospective teachers. Prospective teachers were asked to write the words that come to their minds about the key concepts given to the relevant spaces in the test. Descriptive analysis was used to analyze the data. The responses of each participant regarding the key concepts were evaluated one by one and a frequency table was created according to the number of times the words were repeated. The cut-off point technique of Bahar, Johnstone and Sutcliffe (1999) were taken as the basis in the creation of mind maps. Considering the repetition numbers of the words associated with the key concepts, seven breakpoint ranges were determined. Data f