Teachers in schools and Korean language education researchers have been selecting either quantitative research or qualitative research and using it depending on situation to diagnose and analyze the reality of education, present teaching-learning method and expose their own research subjects. Studies using qualitative research since 1990 have been on the increase and the necessity of the studies has been discussing. Reading is a large part of language use ability for high school students but meaning forming process through reading is so invisible to the naked eye that we can``t easily study it. Reading is a guessing game of sorts and the sooner learners understand this game, the better off they are. The key to successful guessing is to make it reasonably accurate. Qualitative researches are essential to conduct research on guessing occurring before making final products such as speaking and writing and students`` individual difference. According to this necessity, countless qualitative researches are coming out but I question whether these researches meet the requirement of the validity as qualitative researches. This manuscript analyzed 23 dissertations according to 3 standards (The in depth, circularity, integrity) based on the discussion about the validity of Lincoln & Guba(1985), 옥현진(2012), Creswell & Miller(2000). As a result of the analysis, it was found that, on the part of in-depth study, the description on the context of research was insufficient, and on the part of circularity, the level of applying the result of preliminary research to this research or the level of participants`` opinion reflection was insufficient. On the part of integrity, what kinds of common features the various materials have when integrated into research result as well as to collect various forms of materials as much as possible is important. Therefore, this study shows not only qualitative research methods are proper approaches so as to explain students`` thinking process and its context but requirement that they have to get more validity as well. I can accept the fact that preceding researches intended for this study sought research methods having requirement in their way to expose research subjects but I am of the opinion that it is essential to think twice about much more accurate research methods. I strongly argue that this has been accomplished by thinking to improve the validity of reading process and problem-solving strategies.