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AWS Machine Learning Blog· Khaled Thabit·· 12 天前AI 评分50

Property Finder 修复评估偏差提升

Fix evaluation bias to unlock better models on Amazon Bedrock

AI 摘要

数字房产应用 Property Finder 的工程团队发现其评估标签 96.8% 来自单一模型的预测而非人工验证,导致新模型在迁移至 Amazon Bedrock 时因评估偏差而处于劣势。为解决此问题

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Property Finder, a digital real estate application, discovered that 96.8 percent of their evaluation labels were inherited from a single model’s predictions rather than verified by human experts, skewing ground truth toward the incumbent model.

This bias hindered objective model comparison when they migrated their vision AI workload to Amazon Bedrock.

Property Finder processes tens of thousands of property images daily across the Middle East and North Africa (MENA), evaluating 11 quality attributes per image, including watermark detection, room classification, and photo quality.

They needed a more cost-effective option but found that any alternative model was at a disadvantage due to the biased evaluation labels. The challenge was realizing that their evaluation methodology itself was the blocker.

They addressed this by building unbiased ground truth through independent human verification and applying evolutionary prompt optimization on Amazon Bedrock, achieving 86 percent lower cost with higher accuracy.

The process involved an iterative prompt optimization loop, from version v0 to v27, refining prompts based on error analysis and automated optimization, with AI assistants aiding early stages.

This methodology can be applied to other workloads to improve vision model evaluation.

Mohamed Noordeen Alaudeen

Vadim Selyutin

Mina Metias

Mohamed Desouky

Meriem Boughrara

Khaled Thabit

Many teams face similar issues when comparing vision models by using their current model’s outputs as ground truth, creating a circular evaluation that disadvantages alternative models. Property Finder’s evaluation dataset had this problem, with hidden errors in watermark text extraction and photo classification further confirming the bias. To break this cycle, human experts must independently annotate data without referencing previous model outputs, ensuring unbiased ground truth for valid model comparison.

Diagram of the prompt optimization loop: a property image goes to Amazon Bedrock, the predicted attributes are scored with Micro F1 against the expert-annotated development set, error analysis informs the next prompt version, and the loop repeats from v0 to v27.

来源:AWS Machine Learning Blog · aws.amazon.com

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