Yes, but not only that: a well-designed test should also find other things – such as how well a translator can work within a team, or how well a translator follows instructions.

Also, a test sent to a translation vendor (a SLV, say) may not be very useful if it fails to check whether the vendor will, for example, always use their best translators to do the tests, but then entrusts the actual assignment to less qualified translators (because, for example, the best translators are busy on other projects).