The purpose of this study is to investigate the development of students' preconception to Communication media. Recently, students can use various kinds of media such as books, TV and the Internet. Department of Culture, Media and Sport (2001:7) emphasizes the importance of the conscious ability to explain and justify media preference. They argue that this ability enables students to have a wider perspective of choice and to keep critical distance from a plethora of media option. Thus, a number of studies have been conducted with regard to the preconceptions to communication media. The preconception to media is defined as awareness of the degree of liking, level of easiness, level of timeliness and level of reliability (Krendle 1986, Saga 1988, Imai 1993, Gotoh & Ikuta 1999). Ikuta & Gotoh (2001, 2002) have found that students of a wired school like computing and that they do not perceive it as difficult. They attribute the preconception to the experience the students have had in the school. However little is known about how students develop this ability. Therefore this study outlines students' development of preconception to communication media using 'one pair' comparison method. Preconception to media was assessed using the scale from Ikuta & Gotoh (2001). The study investigated how four media activities (reading books, listening to someone, watching TV or videos, and using computers and the Internet) were related with one another by means of the 'one pair' comparison method using four dimensions (preference, ease, speed and reliability) . Five hundred and fifty seven elementary school children, 377 junior high school students, 385 senior high school students and 387 university students participated in this study in 2005. They were provided with a questionnaire regarding the four media activities. The questions were as follows. Which do you prefer to use when carrying out research? (Preference? Which are the easiest to use when carrying out research? (Ease)Which are the fastest to use when carrying out research? (Speed) Which are the reliable to use when carrying out research? (Reliability) The highest frequency of selection was 3 times. The minimum was 0 times. The number of times each activity was selected was analyzed. The results are as follows: 1) Lower Secondary, upper secondary and university students can realize feature of communication media clearly, compared with elementary school children. 2) Regarding level of easiness, elementary school children tend to perceive reading books as easy, while university students tend to perceive the Internet as easy. 3) University students recognize the limitation of reliability of the Internet, compared with elementary school children.DCMS(2001) MEDIA LITERCY STATEMENT:2001 A general statement of policy by the Department for Culture, Media and Sport on Media Literacy and Critical Viewing Skills. Imai, S.?1993?Relationships between learner's preconceptions and teacher's media use. Proceedings of the Ninth Conference on Educational Technology, 298-299 (In JAPANESE) Gotoh, Y. and Ikuta, T. (1997) A study of aptitude of children and their multimedia utilization. Proceedings of the Fifth Joint Conference on Educational Technology, 2, 719-720 Gotoh, Y. and Ikuta, T. (1998) Influence of multimedia utilization on learner's preconceptions to communication media.?Proceedings of the Fifth Conference on Japan Association for the Study of Audiovisual and Broadcast Education, 74-75 Gotoh, Y. and Ikuta, T. (1999) A study of learner's preconceptions to communication media. Japan Journal of Educational Technology, 23,85-88 Ikuta, T. and Gotoh, Y. (1999) A study of Learner's preconceptions to receiving / sending media. Memoirs of Faculty of education and Human Science, Humanities and Social Science, Niigata University, 1(2), 133-150 Ikuta, T. and Gotoh,Y. (2001) A study of children's preconceptions to communication media, Paper presented at the Annual Conference of the British Educational Research Association, University of Leeds, UK Krendle, K?A??1986?Media influence on learning : Examining the role of preconceptions. Educational Communication and Technology Journal ,34,223-234 Saga, H.?1988?Learners' Preconceptions toward Media and the Role of Teachers in Multimedia Utilizing Situations. Bulletin of the National Institute of Multimedia Education, 1?95?115 Saga, H.?1993?Middle School Students' Preconceptions toward Media as Related to Their Learning.? The Japanese Journal of Audio-visual Education, 23, 55-67 Salomon,G.(1981) Communication and Education :Social and Psychological interactions, Sage, Beverly Hills, CA. Salomon,G.(1983) Television watching and mental effort :A social psychological view. In J.Bryant and D.R.Anderson (Eds), Children's understanding of television Academic Press, New York 181-198 Salomon,G.(1984) Television is "easy" and print is "tough". Journal of Educational Psychology, 76, 647-658 Salomon,G., & Leigh,T.(1984) Predispositions about learning form print and television. Journal of Educational Psychology, 34, 119-135Journal of Educational technology