This is the fifth issue (i.e. Volume 3 Issue 1) published by the online journal since its launching two years ago. In this issue, it is our great honour to have a renowned science educator, Prof. Derek Hodson of the University of Torontoto to share with us some of his specialist's thoughts on scientific literacy in our Foreword section. His article is in fact a very comprehensive and critical review of the development and definition of scientific literacy which plays a predominant role in the recent trend of curriculum reform in science education. In the Academic Articles section, we got three peer-reviewed research papers on a fairly diverse aspect of science learning from primary to tertiary education, to wit "constructivist teaching in primary science" (by Winnie SO), "use of IT in the teaching of science: implications on student learning" (by May CHENG and Kai-Ming LI), and "Interactive teaching approach in year one university physics in Taiwan" (Wheijen CHANG, Alister JONES and Rainer KUNNEMEYER).

In the General Articles and Multimedia Resources section, we have seven pieces of articles written by some science and environmental educators in Hong Kong and in mainland China. Four of them are related to the theme of environmental education like "Approaches for environmental education as reflected in CAI (by Yongde HE), "WWF Hong Kong environmental education program" (Sam LEE, Ellen SHEK and Nicole WONG), and "An innovative teaching in ecological laboratory to promote students' creativity" (by Xiao-yong CHEN), and " Casual conversation for modern geographic science" (by Xiaochun TANG). Besides, there is a multimedia article on the use of dataloggers in primary science experiments (by Winnie Wing Mui SO) which contains a number of video clips and powerpoint files available for downloading. We also have an article on "Extracurricular activities in science education for Beijing youth" (by Lin ZHOU, Baoquan LI and Jingling LIU) and another article on "A case study of school-based science curriculum development: Overview of project approach and process of implementation" (by Teresa WONG). As usual, all those articles are available for retrieval in the Adobe Portable Document Format (pdf) and for all Chinese articles , there exist the Simplified Chinese version (in GB coding) as well.

Finally, we would like to express our sincere thanks to Prof. Russell Tytler (Deakin University), Prof. Chao-Ti Hsiung (Normal Taipei Teachers' College), and Prof. John Loughran (Monash University) for providing the critical peer-review of those research papers. Besides, I am very grateful to all members of our Editorial Board who help me in reviewing and polishing all other contributed articles. Thanks are also due to all those who have contributed articles in this issue and to all research assistants and colleagues in the HKIEd Science Department who offered their help in developing and promoting this online periodical.