Every group is represented in many ways as an epimorphic image of a free group. It seems therefore futile to search for methods involving generators and relations which can be used to detect the structure of a group. Nevertheless, results in the indicated direction exist. The clue is to ask the right question. Classical geometry is a typical example in which the factorization of a motion into reflections or, more generally, of a collineation into central collineations, supplies valuable information on the geometric and algebraic structure. This mode of investigation has gained momentum since...

R.C. Bose: Graphs and designs.- R.H. Bruck: Construction problems in finite projective spaces.- R.H.F. Denniston: Packings of PG(3, q).- J. Doyen: Recent results on Steiner triple systems.- H. Luneburg: Gruppen und endliche projektive Ebenen.- J.A. Thas: 4-gonal configurations.- H.P. Young: Affine triple systems.

Every group is represented in many ways as an epimorphic image of a free group. It seems therefore futile to search for methods involving generators and relations which can be used to detect the structure of a group. Nevertheless, results in the indicated direction exist. The clue is to ask the right question. Classical geometry is a typical example in which the factorization of a motion into reflections or, more generally, of a collineation into central collineations, supplies valuable information on the geometric and algebraic structure. This mode of investigation has gained momentum since...