As mentioned in the last issue, we shall publish 3 issues in year 2004 and so this is the April or First Issue of Volume 5 and the remaining two issues shall be released by the end of August and December, 2004. A promotional leaflet which contains the Table of Contents for the last three published issues has been published and mailed to all primary and secondary schools in Hong Kong.

In this issue, we have a very great pleasure to get Prof. Robert E. YAGER (Professor of Science Education, University of Iowa), a world renowned science educator - the father of the STS movement as recognised by many researchers in this field, to write for us a review-oriented foreword called "Using Social Issues as Contexts for K-16 Science Education". In the Academic Articles Section, there are three articles written by 11 authors in Turkey, Taiwan and Singapore. Starting from last issue, we add a new section called the Exemplary Teaching Methods which has three articles on using various effective teaching methods such constructivist view of learning, demonstration and group investigation for classroom teaching of specific science topics. For the General Articles and Multimedia Resources section, there are two articles which introduce some interesting teaching materials and activities for teaching physics. Altogether this issue contains 50 files (nearly 400 MB in total size) of videoclips, resources and pdf version of articles available for downloading in our Download section.

Finally, we would like to express our sincere thanks to the 14 external referees and all members of our Editorial Board who have carefully and critically reviewed those manuscripts considered for publication in this issue. Thanks are also due to all persons who have contributed articles in this issue and to all research assistants and colleagues in the HKIEd Science Department who offered their kind assistance in developing and promoting this online periodical.