Martin LeVoi referred to ‘critical mass’ – the size that an online group needs to be in order to be effective. Thought I’d go and check this out. ‘Critical mass’ doesn’t appear to be a technical term in regular use in the literature, but there is some discussion of group size.
Glass and Smith looked at 80 studies of F2F classes which concluded that smaller clases were better with respect to student achievement, classrom processes and teacher and student attitudes. Hayes suggested that distance learners need small groups so they can share and critique project work. He felt that a group of five would allow students to enjoy a rich exchange and feel part of a learning comunity without wasting time sifting through umpteen postings.
A virtual community must have enough participants to allow a significant level of interaction. Gilly Salmon suggests that an ideal size is up to nine.
Four is often considered the ideal in F2F situations because the group is large enough to hold diverse opinions, to draw on different experiences and to approach the subject in different ways. It is not so big that someone can hide and not pull their weight.
Rice suggests a critical mass of 8-10 – generating sufficient volume of interactions without being overwhelming.