Towards Evaluation Engineering: An Empirical Study of ML Evaluation Harnesses in the Wild

Hugging Face Daily Papers Papers
empirical-study ml-evaluation evaluation-harnesses software-engineering machine-learning-infrastructure

Summary

This paper presents an empirical study of 57 ML evaluation harnesses, identifying common operational challenges and root causes across five workflow stages, advocating for evaluation engineering as a distinct software engineering concern.

Evaluation harnesses are software systems that orchestrate model evaluation by managing model invocation, data loading, metric computation, and result reporting. Despite their critical role in machine learning infrastructure, their operational challenges and engineering concerns have received limited attention so far. We present an empirical study of 57 evaluation harnesses, deriving a five-stage harness model and classifying 16,560 issues by workflow stage and root cause. Most harness operational challenges concentrate in the Specification stage (41.4% of issues), where harnesses integrate external models, datasets, and scoring judges. The three most frequent root causes of operational challenges are unimplemented features (24.3%), documentation gaps (20.3%), and missing input validation (17.2%), which together account for 61.7% of classified issues, spanning both defects in existing functionality and capability gaps that block intended workflows. Root causes also vary by workflow stage: environment incompatibility and external dependency breakage account for 36.2% of provisioning issues, whereas algorithmic error (25.9%) and validation gap (22.5%) dominate assessment issues. Together, these contributions establish an empirical foundation for treating evaluation engineering as a distinct software engineering concern.
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Paper page - Towards Evaluation Engineering: An Empirical Study of ML Evaluation Harnesses in the Wild

Source: https://huggingface.co/papers/2605.24213

Abstract

Evaluationharnessesaresoftwaresystemsthatorchestratemodelevaluationbymanagingmodelinvocation,dataloading,metriccomputation,andresultreporting.Despitetheircriticalroleinmachinelearninginfrastructure,theiroperationalchallengesandengineeringconcernshavereceivedlimitedattentionsofar.Wepresentanempiricalstudyof57evaluationharnesses,derivingafive-stageharnessmodelandclassifying16,560issuesbyworkflowstageandrootcause.MostharnessoperationalchallengesconcentrateintheSpecificationstage(41.4%ofissues),whereharnessesintegrateexternalmodels,datasets,andscoringjudges.Thethreemostfrequentrootcausesofoperationalchallengesareunimplementedfeatures(24.3%),documentationgaps(20.3%),andmissinginputvalidation(17.2%),whichtogetheraccountfor61.7%ofclassifiedissues,spanningbothdefectsinexistingfunctionalityandcapabilitygapsthatblockintendedworkflows.Rootcausesalsovarybyworkflowstage:environmentincompatibilityandexternaldependencybreakageaccountfor36.2%ofprovisioningissues,whereasalgorithmicerror(25.9%)andvalidationgap(22.5%)dominateassessmentissues.Together,thesecontributionsestablishanempiricalfoundationfortreatingevaluationengineeringasadistinctsoftwareengineeringconcern.

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