Recent years have seen a substantial growth in research that probes children's ideas about natural phenomena. This paper places that research in a context which enables comprehension of how it informs and influences the practice of science education. To this end, past, present, and future styles of research are considered to: (1) demonstrate links between alternative conceptions research and earlier investigations of science learning; (2) identify new issues of importance for science education in current research on children's ideas; and (3) indicate directions that research should take. Consideration of past research inevitably involves an elaboration of personal epistemologies. Therefore, the first section of the paper considers the evolution over the last 20 years of the general direction of science education research at Monash University. More specific research on students' alternative conceptions of science are then outlined. This leads to a consideration of present research in terms of the relations between research and practice, and of the implications for further development. The future developments described focus particularly on research on the strategies used by learners, and on the continued growth of interaction between research and practice. The paper concludes with a discussion of emerging styles and purposes in science education research. (JN)