Wayne Matheson & John McLeish 
Psychology of the Learning Group [PDF ebook] 

Originally published in 1973, this work takes a hard look at the claims made for the small group as a learning medium (lecture, structured discussion, 'sensitivity’, training groups etc.). Various theories of group dynamics, leadership function and learning process are looked at critically on the basis of actual research findings. It was intended for students of social psychology and anyone teaching or training to teach at Further Education level at the time, and will still be of interest in its historical context today.