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Dataless Knowledge Fusion by Merging Weights of Language Models

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arxiv 2212.09849 v6 pith:5ZWFXW5R submitted 2022-12-19 cs.CL cs.LG

Dataless Knowledge Fusion by Merging Weights of Language Models

classification cs.CL cs.LG
keywords modelsdatamodelindividualtrainingknowledgemergingmethod
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved
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Fine-tuning pre-trained language models has become the prevalent paradigm for building downstream NLP models. Oftentimes fine-tuned models are readily available but their training data is not, due to data privacy or intellectual property concerns. This creates a barrier to fusing knowledge across individual models to yield a better single model. In this paper, we study the problem of merging individual models built on different training data sets to obtain a single model that performs well both across all data set domains and can generalize on out-of-domain data. We propose a dataless knowledge fusion method that merges models in their parameter space, guided by weights that minimize prediction differences between the merged model and the individual models. Over a battery of evaluation settings, we show that the proposed method significantly outperforms baselines such as Fisher-weighted averaging or model ensembling. Further, we find that our method is a promising alternative to multi-task learning that can preserve or sometimes improve over the individual models without access to the training data. Finally, model merging is more efficient than training a multi-task model, thus making it applicable to a wider set of scenarios.

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Forward citations

Cited by 20 Pith papers

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  5. Generalizing the Geometry of Model Merging Through Frechet Averages

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