Testing Finnish Customer-Service AI Agents: FI/EN Quality and Parity

Why Finnish deserves its own test coverage

Finnish morphology, compound words, inflection and local service terminology can change retrieval and interpretation. More importantly, many companies maintain policies and knowledge articles unevenly across languages. An agent may therefore retrieve different evidence for the same customer intent.

Build paired FI/EN cases

Create paired test cases that express the same business intent in Finnish and English. Keep the expected outcome identical unless the business rule itself differs by language or market. Examples include return eligibility, delivery conditions, membership benefits, cancellation rules and mandatory escalation.

Score the business outcome, not translation quality

A Finnish answer does not need to be a literal translation of the English answer. It must produce the same approved entitlement, restriction, price and next action. Track language style separately from business correctness.

Measure the language success gap

A simple metric is Finnish task-success rate minus English task-success rate. If Finnish passes 86% and English 95%, the gap is -9 percentage points. The number is most useful when the cases are genuinely equivalent and repeated over time.

Include Finnish edge cases

Test colloquial wording, inflected product names, compound nouns, abbreviations, customer typos and code-switching where they occur in real support. Also test whether a Finnish question retrieves an English policy and whether that policy is applied correctly.

Watch for regressions after knowledge updates

Language-specific regressions often appear after a knowledge-base edit or translation update. A paired benchmark makes the change visible: the English case may remain stable while the Finnish case starts using stale or incomplete evidence.

Do not overclaim from a small sample

Three successful Finnish probes do not prove that the system is safe for all Finnish users. Report the number and type of tested cases. Expand coverage around high-volume and high-cost customer intents.