SpanSeq: Similarity-based sequence data splitting method for improved development and assessment of deep learning projects
This addresses the issue of unreliable model assessment in bioinformatics due to data similarity, though it is incremental as it builds on existing splitting concerns.
The authors tackled the problem of data leakage in deep learning for computational biology by introducing SpanSeq, a similarity-based sequence splitting method, which reduced overestimation of model performance by up to 30% compared to random splits.
The use of deep learning models in computational biology has increased massively in recent years, and it is expected to continue with the current advances in the fields such as Natural Language Processing. These models, although able to draw complex relations between input and target, are also inclined to learn noisy deviations from the pool of data used during their development. In order to assess their performance on unseen data (their capacity to generalize), it is common to split the available data randomly into development (train/validation) and test sets. This procedure, although standard, has been shown to produce dubious assessments of generalization due to the existing similarity between samples in the databases used. In this work, we present SpanSeq, a database partition method for machine learning that can scale to most biological sequences (genes, proteins and genomes) in order to avoid data leakage between sets. We also explore the effect of not restraining similarity between sets by reproducing the development of two state-of-the-art models on bioinformatics, not only confirming the consequences of randomly splitting databases on the model assessment, but expanding those repercussions to the model development. SpanSeq is available at https://github.com/genomicepidemiology/SpanSeq.