  Small Group evolution has been of central importance in social sciences and
also in the industry for understanding dynamics of team formation. While most
of research works studying groups deal at a macro level with evolution of
arbitrary size communities, in this paper we restrict ourselves to studying
evolution of small group (size $\leq20$) which is governed by contrasting
sociological phenomenon. Given a previous history of group collaboration
between a set of actors, we address the problem of predicting likely future
group collaborations. Unfortunately, predicting groups requires choosing from
$n \choose r$ possibilities (where $r$ is group size and $n$ is total number of
actors), which becomes computationally intractable as group size increases.
However, our statistical analysis of a real world dataset has shown that two
processes: an external actor joining an existing group (incremental accretion
(IA)) or collaborating with a subset of actors of an exiting group (subgroup
accretion (SA)), are largely responsible for future group formation. This helps
to drastically reduce the $n\choose r$ possibilities. We therefore, model the
attachment of a group for different actors outside this group. In this paper,
we have built three topology based prediction models to study these phenomena.
The performance of these models is evaluated using extensive experiments over
DBLP dataset. Our prediction results shows that the proposed models are
significantly useful for future group predictions both for IA and SA.
