Explaining systems: Investigating middle school students' understanding of emergent phenomena

Science, as with all cognitive activities, is fundamentally a matter of interpretation, sense-making, and explanation. This study focused on a small group of middle school students as they developed understanding of a particular type of phenomena: emergent systems. Such systems are notable in that macro-level properties emerge as the result of micro-level interactions between system components. I describe students' initial understanding of emergent systems, as well as the ways in which their thinking came to reflect the following heuristics: (a) recognition that there may not be a singular causal force underlying the system; (b) distinguishing between micro- and macro-levels of analysis; and (c) comprehending that even small changes at the micro-level can have significant effects at the macro-level (Resnick, 1994). I conclude by considering some implications for science education. © 2000 John Wiley & Sons, Inc. J Res Sci Teach 37: 784–806, 2000