  Graph neural networks (GNNs) have shown remarkable performance on diverse
graph mining tasks. Although different GNNs can be unified as the same message
passing framework, they learn complementary knowledge from the same graph.
Knowledge distillation (KD) is developed to combine the diverse knowledge from
multiple models. It transfers knowledge from high-capacity teachers to a
lightweight student. However, to avoid oversmoothing, GNNs are often shallow,
which deviates from the setting of KD. In this context, we revisit KD by
separating its benefits from model compression and emphasizing its power of
transferring knowledge. To this end, we need to tackle two challenges: how to
transfer knowledge from compact teachers to a student with the same capacity;
and, how to exploit student GNN's own strength to learn knowledge. In this
paper, we propose a novel adaptive KD framework, called BGNN, which
sequentially transfers knowledge from multiple GNNs into a student GNN. We also
introduce an adaptive temperature module and a weight boosting module. These
modules guide the student to the appropriate knowledge for effective learning.
Extensive experiments have demonstrated the effectiveness of BGNN. In
particular, we achieve up to 3.05% improvement for node classification and
6.35% improvement for graph classification over vanilla GNNs.
