When can in-context learning generalize out of task distribution?

The research empirically investigates the role of pretraining distribution and a new concept of task diversity in the emergence of ICL, particularly using models trained on linear functions. Findings indicate that increasing task diversity causes transformers to shift from a specialized solution to one that can generalize across the entire task space, a transition also observed in nonlinear regression problems. The authors constructed a phase diagram to characterize how task diversity and the number of pretraining tasks interact, while also examining the influence of factors like model depth and problem dimensionality.