Comparing Ordered Sets Generated by Different Data-Processing Engines

A technique updates a first data-processing engine based on reference information produced by a second data-processing engine. The technique involves obtaining ordered sets of result items from both engines, where the result items produced by the second engine serve the role of the reference information. The technique then produces accuracy information by assessing the accuracy of the first-set result items relative to the second-set result items. The accuracy information is a set-wide assessment that reflects how well the first-set result items match the second-set result items, taking into account the similarity between pairs of result items and the ordering of result items in the ordered sets. The technique then modifies a configuration of the first data-processing engine based on the accuracy information to improve its quality. In some implementations, the first and second data-processing engines are first and second map engines that generate routes through a physical space.