Science students find heat, temperature, enthalpy and energy in chemical reactions to be some of the most difficult subjects. It is crucial to define their conceptual understanding level in these subjects so that educators can build upon this knowledge and introduce new thermodynamics concepts. This paper reports conceptual understanding levels of high school students of common thermodynamics subjects such as heat, temperature, enthalpy and energy changes in chemical reactions. The sample of the study was composed of 418 randomly selected students from 11 different high schools. A cross sectional survey model was employed in this study. Data were collected through the Conceptual Understanding Test (CUT), which consists of 16 questions. Cronbach's alpha reliability coefficient for the test was 0.72. Besides, interviews were conducted with 10 students to get qualitative data about their beliefs on the subject. The results of the study indicated that students' level of conceptual understanding in thermodynamics concepts is very low. It was observed to be especially low for the concepts of (1) relationship between energy, enthalpy and bonds in chemical reactions, (2) energy and catalysts in chemical reactions, (3) changes in heat, temperature and enthalpy during change of state, and (4) the relationship between heat, temperature, mass and specific heat. Most of the students in this study do not fully understand common thermodynamics concepts although they have been studying these topics since primary school.

The language learning strategy question has been debated on a number of levels, including definition, the strategy/success relationship and strategy coordination. In addition, awareness has been steadily growing of the importance of taking an holistic view of the strategy phenomenon and examining strategies not just in isolation but as part of an overall picture which includes learning situation, learning target and individual learner characteristics. This article will first of all review the literature and the previous research on these controversial issues, and suggest a workable definition. Then, in order to illustrate the importance of such an holistic view, the results of a small scale study which looks at the strategies used by 16 successful language learners who were all either teaching English or teaching in English at university level will be reported. The quantitative results indicated that these successful learners used many strategies, especially those that suited their goals and their situations; they also frequently used and carefully orchestrated strategy repertoires which suited their own individual needs. The responses of one highly successful respondent were also examined qualitatively. The implications of these findings and the importance of viewing learners holistically are discussed and suggestions are made for ongoing research.