Digital textbooks have been used extensively worldwide. From the viewpoint of technological development, the definitions and the needs of digital textbooks have been discussed in this article. Further, the current adoption of digital textbooks internationally was illustrated and the policies and experience of several countries were compared. Then, several research findings related to digital textbook design principles and usability tests have been reviewed. Finally, the article summarized reflections on current trends and issues in the design and development of digital textbooks, and provided suggestions for future development in Taiwan.

　　This study designed a correlation analysis method that focused on textbook content and objectives. Based on a mechanism similar to blind test, this method used a team of experts to survey texts, pictures, charts, and instruction activities employing a comprehensive and interpretative approach, converting textbook content into instruction objectives and competence indicators. Another team of experts further compared the instruction objectives and competence indicators with the original instruction objectives and competence indicators listed in the textbooks. Using the graphics and data, the semantic association of the two sets of instruction objectives and the statistic correlation of the two sets of competence indicators are presented for further discussion and examination. The applicability of this analysis method was inspected in accordance with features particular to this research method and requisites that are to be met in method design, and the processes and results of empirical trial. The utility, objectivity and conciseness of this analysis method could be verified. However, some coordination with textbook accreditation and evaluation authorities were required to enhance the feasibility in terms of time and finance.

　　This study compared the algebra content of instructional materials in the most popular elementary school mathematics textbook series used in Taiwan, Finland and Singapore. The mathematics instructional materials reviewed were KangHsuan Mathematics, the WSOY LASKUTAITO in English, the MCE My Pals are Here! Maths used in Taiwan, Finland, and Singapore, respectively. The research method employed was content analysis. Mathematical problems were the unit of analysis and they were classified based on their cognitive types, contexts and representational forms. Findings showed that the percentage of algebra problems presented in the textbooks in these three countries was not high, only about 7% to 13%. In sample problems, Taiwan and Singapore presented a detailed problem-solving process, but Finland only offered brief descriptions or definitions. We found the ratio of different types of problems in textbooks to be similar in the three countries with most of the problems classified as ‘procedure without connection’ in each country. As to problem contexts, most algebra problems in Taiwan were contextual problems in nature, but in Finland and Singapore, were classified as non-contextual problems. When the representational forms of problems was examined, we found that most problems were presented in word form in Taiwan, but most frequently in a purely mathematical form in Finland and Singapore.