This paper presents an overview of several research projects involving grou
ps working with science simulations, in particular with relation to gender
effects on science learning. The groups of learners discussed include: pair
s of adults working together on computer simulations at a distance, or side
by side, pairs of 15 year-olds working with computer simulations, and larg
er groups of younger children working co-operatively on combinations of com
puter simulations and real science experiments. While collaboration may be
in many respects a good thing, there is a growing realisation amongst scien
ce educators that particular features of the learning experience are altere
d by the Sender composition of the groups. These features range from the wa
y in which conflict is expressed or the task perceived, to differences in t
he way that dialogue is used. These findings need to be considered together
with evidence concerning the barriers which girls experience while learnin
g science. This work is reviewed, together with some research projects invo
lving students working collaboratively with computers on science topics. Ge
nder differences in the most productive way of forming groups to work at th
e computer on science simulations are considered. (C) 2000 Published by Els
evier Science Ltd.