Balancing effectiveness and flakiness of non-deterministic machine learning tests

Testing Machine Learning (ML) projects is challenging due to inherent non-determinism of various ML algorithms and the lack of reliable ways to compute reference results. Developers typically rely on their intuition when writing tests to check whether ML algorithms produce accurate results. However, this approach leads to conservative choices in selecting assertion bounds for comparing actual and expected results in test assertions. Because developers want to avoid false positive failures in tests, they often set the bounds to be too loose, potentially leading to missing critical bugs. We present FASER – the first systematic approach for balancing the trade-off between the fault-detection effectiveness and flakiness of non-deterministic tests by computing optimal assertion bounds. FASER frames this trade-off as an optimization problem between these competing objectives by varying the assertion bound. FASER leverages 1) statistical methods to estimate the flakiness rate, and 2) mutation testing to estimate the fault-detection effectiveness. We evaluate FASER on 87 non-deterministic tests collected from 22 popular ML projects. FASER finds that 23 out of 87 studied tests have conservative bounds and proposes tighter assertion bounds that maximizes the fault-detection effectiveness of the tests while limiting flakiness. We have sent 19 pull requests to developers, each fixing one test, out of which 14 pull requests have already been accepted.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Computer Science

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2024

Author dc:creator

• Xia, Chunqiu

Contributors dc:contributor

• Zhang, Lingming

• Machine Learning
• Software Engineering

Statement dc:rights

• Copyright 2024 Chunqiu Xia

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/127399

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F127399