The main problems in assessing the information quality of a particular kind of location-based service are described. Verifying the conformance of query results to the real world is identified as the most expensive problem. An approach from database quality assessment is adapted, by combining it with conventional software reliability testing, so that the verification can be replaced with two significantly easier test obligations. The resulting procedure should achieve a good compromise between the confidence level of the results and the testing effort. The approach seems also applicable to a broader range of systems.