Students have too much experience at running experiments with insufficient replication. And employers are telling us they want students who know how to make group work succeed. Replication is important. Each student is expected to calculate the means and std. The advantage of this approach is that a fairly large data base can be obtained, and meaningful interpretation of the results can be made rather than attempting to make sense out of single observations.
Students also learn about biological variability and designing experiments with adequate controls.
Richard Walker Biological Sciences Univ. Because I stress lab work heavily in the classroom, my students learn quickly that they had better know the labs well, but it does take dedication on the part of the classroom instructor. A passive lab instructor sitting at the front desk is death to these labs. I have less concern about group work, however, for two reasons. The first is that, for some labs, we have a set-up similar to the one Richard describes, where data is pooled and shared.