FIELD

The technology described herein relates generally to statistical procedures evaluating test security and more specifically to detecting unusually frequent exactly matching and nearly matching test responses.

BACKGROUND

In investigations of unusual testing behavior, a common question is whether a specific pattern of responses occurs unusually often within a group of test takers. Modern communication techniques can in some cases permit quite large numbers of test takers to share keys, or common response patterns, to the entire test. Test takers using or sharing the keys are not limited to the same testing location and may have no connection whatsoever outside of utilizing the same key sources. As such, automated test security procedures are an important and challenging research area, specifically in tests administered to a large number of test takers or across a wide geographic region.

SUMMARY

In accordance with the teachings herein, computer-implemented systems and methods are provided for detecting unusually frequent exactly matching and nearly matching test responses. An embodiment of a method for detecting unusually frequent exactly matching and nearly matching test responses comprises receiving a plurality of test responses for each of a plurality of test takers, wherein each test response corresponds to a question on a test distributed to the plurality of test takers. The method further comprises identifying evidence of a circulated key from the plurality of test responses by detecting two or more test takers with exactly matching test responses for a plurality of questions, wherein the exactly matching test responses correspond to a response pattern from the circulated key. The method further comprises analyzing the strength of the evidence of the circulated key by determining a probability that the two or more test takers would produce exactly matching test responses, wherein the strength of the evidence is inversely related to the probability. The method further comprises identifying test takers with nearly matching test responses to the circulated key and tagging the test takers with exactly matching and nearly matching test responses for further investigation.

A computer-implemented system for detecting unusually frequent exactly matching and nearly matching test responses is further described herein, wherein the system comprises one or more data processors and one or more computer-readable storage mediums encoded with instructions for commanding the one or more data processors to execute steps that include the aforementioned method. A non-transitory computer-readable storage medium is further described herein, wherein the storage medium comprises instructions for which when executed cause a processing system to execute steps comprising the aforementioned method.

