Textbooks in Taiwan under the trend of reforms have completely released. It represented the promotion the decentralization of textbooks, enhance the professional autonomy of teachers, increase the diversity of teaching materials, and improve the editorial reforms of booksellers in textbook editing (Peng & Zhan, 2011). Students rely on textbooks a lot in learning. Textbooks which contain text and graph determine the teaching content about 75% to 90% (Wu & Wu, 2015).  For a long time, school teaching focused on text not graph. Few studies mentioned how to use diagrams to influence students' learning (Slough & McTigue, 2013). However, not all the graphics are benefit in learning. In fact, many poor-designed textbooks not only lack links but also ignore students’ prior knowledge. So some textbooks hadn’t produced important function to promote meaningful learning for students (Wu & Wu, 2015; Liu & Treagust, 2013).

    Through the diversity of the textbooks censored by National Academy for Education Research in Taiwan, the appropriate version is selected to provide teacher teaching and student learning. Textbooks are diversified in terms of theme, style and design layout, besides the degree of difficulty and content of material are also varied (Sheu, 2015). In recent years, scholars have proposed indicators for the selection of textbooks, including teaching, content, physics and publication attributes (Hsu & Chen, 2013). Briefly, teachers choose textbooks focus on different orientations, and selection well-designed textbooks are much worth to in-depth exploration. Through the graphic layout of physical attributions, teachers can use logical integration of text and graph to enhance students' learning benefit.

    Mayer (2005) based on dual coding theory and cognitive load theory, further proposed cognitive theory of multimedia learning (CTML). Learners can simultaneously process text and images with more efficiency than work with text or images alone, and integrate teaching materials into more in-depth concepts (Clark & Mayer, 2016). Individuals consisted empirical mental representations to generate meaningful learning through active processing contain selection, organization, and integration (Mayer, 2005). That is to say, in-depth understanding of learning from multimedia teaching materials includes focusing on important teaching materials, mentally organizing into a consistent cognitive structure and integrating relevant prior knowledge (Rusanganwa, 2015). Cognitive processing capacity of memory is limited (Sorden, 2012). Therefore, complementing each other through text and image channels and reinforce the comparisons, and monitoring not to overload the limited capacity of cognitive processing will help to enhance the effectiveness of learning. The design of textbooks will affect the cognition process of students' learning (Baek & Monaghan, 2013). So textbooks play an important role in student learning. Appropriate-designed teaching materials enable teachers to organize content and reduce extraneous cognitive load and promote germane cognitive load (Sorden, 2012). Therefore, the teachers using the systematic textbook not only assist in the effective teaching of knowledge, but also help students improve their learning efficiency to make meaningful learning. Therefore, teachers view textbooks as the medium of knowledge transfer (Gurung & Landrum, 2012).

    Now, there are many booksellers in Taiwan, but few researchers are concerned with the relationship between layout and teacher selection of textbooks. Therefore, this study attempts to further understand the teacher's awareness of the use of text and graphics in the current version of the textbooks. Form teacher’s perspectives to explore layout editing in teaching activities on the current using textbooks. Specifically, the research questions are as follows: (1) what reasons did teachers choose this version? (2) what is the orientation of the selection of textbooks, and what are the reasons?

This research adopts the grounded theory of qualitative research to focus on expanding the significance of research participants' experience to develop the theory. Through semi-structured interviews explore the view of teachers about what the consideration to select the current textbook version. Preliminary drafted interview outlines were defined research questions and interviewed participants. Then returned to the data itself and revised it to form the final semi-structured outline. Research participants were selected by purposive sampling to recruit in-service teachers with rich practical experience in teaching. The participants are 30 to 35 years old females teaching different subjects in junior high school of the southern metropolitan area in Taiwan. Data collected by different time are analyzed using the constant comparative method, through open coding, axial coding, and selective coding analysis to generate different categories of concepts and establish a theory (Oktay, 2012; Corbin & Strauss, 2007). At the same time, memos are used to confirm the theoretical sensitivity, and theoretical sampling has filled the gap by continuously follow-up interviewing the participants. The data are continuously collected until theoretical saturation is reached. The research course was from December 2017 to June 2018. The participants conducted one hour semi-structured interviews each time. There were four times in total and last one focused on the theoretical map checking. Therefore, the implementation of the interview conducted in this study can illustrate the current situation of teachers using textbooks, and awaken teachers to use appropriate textbooks to enhance meaningful learning. The research follows the research ethics and participants signed informed consent. To improve the trustworthiness, the study will triangulate the data, including audio-recorded interview, related documents, and memos, etc. Collecting different sources of data to interactive examine makes the collected data more completed and contextual. The participants are asked to re-confirm the content of interviews’ verbatim drafts to enhance the credibility. The researchers marked important description fragments of the verbatim draft, abstracted what referred to the concepts, and examined the confirmability by checking the interviews and other materials back and forth continuously. This research was guided by experienced scholars to develop theoretical maps and storyline, which were sent to the interviewers for review and revisions as a result of this study.

Textbook is an important medium for teaching and learning (Gurung & Landrum, 2012). Teachers have professional autonomy to select textbook assisting in teaching. The design of textbooks will influence the cognitive learning process of students (Baek & Monaghan, 2013). Teacher need to consider different levels included teaching materials, teacher teaching and student learning. This study attempts to refine the theoretical model about the considerations of junior high school teachers selecting textbooks used in class. First, in terms of material teachers selected the textbooks on fore principles: the priority of difficulty level, large quantity range, the curriculum guidelines in Taiwan, and the strong structure integration. It explores the integration of graphics and texts further. But the viewpoint of adoption is still the 'text-centered' not 'student-centered' (Mao, 2012). Secondly, considering the teaching, teachers’ the class time and teaching strategy are also included in the evaluation of teachers' choice of textbooks. Last, well-designed textbooks can make students themselves read to understand and comprehend the content. The core knowledge of the textbook presents a conceptual map. The one of the key textbook selection criterion is the integration of graphics and texts (Slough & McTigue, 2013). The description of the text combines with the organized graphics will promote lecture effective to enhance students clearly clarify the concept. Each link is intertwined into a tight network. Teachers selecting textbooks focus on the layout not only include knowledge content of curriculum guidelines published by the Ministry of Education in Taiwan, but also enable to let students easy-understand to self-study. Besides, the graphic design is better to matching with the teacher's teaching strategy. Therefore, by choosing a well-designed textbook, it is not only beneficial for teachers teach incomprehensible concepts of knowledge, but also affects students' cognitive process of knowledge understanding.

Baek, E. & Monaghan, J. (2013).Journey to textbook affordability: An investigation of students' use of eTextbooks at multiple campuses. International Review of Research in Open and Distance Learning, 14(3), 1-26. Clark, R. C., & Mayer, R. E. (2016). E-learning and the science of instruction: Proven guidelines for consumers and designers of multimedia learning. Hoboken, New Jersey: Wiley. Corbin, J., & Strauss, A. (2007). Basics of Qualitative Research: Techniques and Procedures for Developing Grounded Theory. Sage. Gurung, R., & Landrum, R. E. (2012). Comparing Student Perceptions of Textbooks: Does Liking Influence Learning?. International Journal of Teaching and Learning in Higher Education, 24(2), 144-150. Hsu, M. Y. & Chen, H. W. (2013). J A Study of Selection of Science and Technology Textbooks Used in Elementary Schools in Greater Taipei Area. Journal of Textbook Research, 6(3), 1-34. Liu, Y., & Treagust, D. (2013). Content analysis of diagrams in secondary school science textbooks. In M. S. Khine (Ed.), Critical Analysis of Science Textbooks (pp. 287-300). Netherlands: Springer. Mao, C. J. (2012). Searching for the Greatest Common Denominator: Analysis of the Compilation and Review Process for High School History Textbooks. Contemporary Educational Research Quarterly, 20(1), 83-122. Mayer, R. E. (Ed.). (2005). The Cambridge handbook of multimedia learning. New York: Cambridge University Press. Oktay, J. S. (2012). Grounded theory. UK: Oxford University Press. Peng, C. L. & Zhan, M. H. (2011). An Analysis of the Controversy over the Policy of Concurrently Reviewing and Approving Publicly and Privately Compiled Textbooks. Journal of Textbook Research, 4(1), 1-30. Rusanganwa, J. A. (2015). Developing a multimedia instrument for technical vocabulary learning: A case of EFL undergraduate physics education. Computer Assisted Language Learning, 28(2), 97-111. Sheu, P. H. (2015). A Study of Elementary School English Teachers' Textbook Selection Competence in Taipei City. Elementary Education, 55(1), 140-151. Slough, S. W., & McTigue, E. M. (2013). Development of the graphical analysis protocol (GAP) for eliciting the graphical demands of science textbooks. In M. S. Khine (Ed.), Critical analysis of science textbooks: Evaluating instructional effectiveness (pp. 17-33). New York: Springer. Sorden, S. D. (2012). The Cognitive Theory of Multimedia Learning. In B. J. Irby, G. Brown, R. Lara-Alecio, & S. Jackson (Eds.), The Handbook of Educational Theories (pp. 155-168). Charlotte: Information Age. Wu, J. H. & Wu, J. S. (2015). Ideal textbook design based on learning-centered. Taiwan Educational Review Monthly, 4(8), 157-160.