How to evaluate entity resolution tools

A practical checklist for evaluating ER tools: scale, explainability, PPRL support, threshold tuning UX, audit trail, deployment model.

Most ER tool evaluations end up rerunning the same demo dataset against three or four vendors and comparing match counts. That misses the questions that bite later. This is the checklist worth using.

The seven questions

  1. Scale. Does the tool handle your row count without falling over? Benchmark at your actual data volume, not the vendor's reference deck. A tool that works at 100k rows can fail at 5M because blocking degrades, memory pressure spikes, or the clustering step becomes O(n^2). Ask for runtime numbers at 10x your current scale.

  2. Explainability. When the tool merges two records, can you see why? A reviewer should be able to inspect which fields matched, which scorers fired, and what threshold was crossed. If the answer is a black-box score, debugging mis-merges becomes guesswork. The current state of explainability in goldenmatch is the postflight blob plus per-pair scorer breakdown.

  3. Threshold tuning UX. How do you actually move the threshold? A slider with live precision/recall feedback is the gold standard. A YAML config you edit and rerun is acceptable. A binary "fast/accurate" preset is not. The threshold-tuning guide explains why interactive tuning matters.

  4. PPRL support. If your data needs to stay inside an organizational boundary, can the tool match across boundaries without revealing raw identifiers? Most commodity tools say no. The PPRL page covers what to ask for.

  5. Audit trail. Can you reconstruct who approved which merge and when? For regulated data (healthcare, finance), this is a hard requirement, not a feature. Hash-chained logs and per-action diffs are the bar.

  6. Deployment model. SaaS, self-hosted, or hybrid? Where does the data sit during processing? "We process in your VPC" and "we process in our cloud with a DPA" are very different answers. Pin down the actual data flow.

  7. Cost shape. Per-record, per-seat, per-cluster, or flat tier? Match it to how your usage will grow. A per-record price that looks fine at 1M rows can be untenable at 50M.

Skip the bake-off until last

Run the seven-question pass before you commit to a head-to-head bake-off. Bake-offs are expensive in engineering time. Eliminating tools that fail one of the questions above saves weeks.