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Equivalence Class Verification and Oracle-Free Testing Using Two-layer Covering Arrays



David R. Kuhn, Raghu N. Kacker, Yu Lei, Jose Torres-Jimenez


This short paper introduces a method for verifying equivalence classes for module/unit testing. This is achieved using a two-layer covering array, in which some or all values of a primary covering array represent equivalence classes. A second layer covering array of the equivalence class values is computed, and its values substituted for the equivalence class names in the primary array. It is shown that this method can also detect certain classes of errors without a conventional test oracle, and an illustrative example is given.
Proceedings Title
4th International Workshop on Combinatorial Testing
Conference Dates
April 13-17, 2015
Conference Location
Conference Title
IEEE International Conference on Software Testing, Verification and Validation


combinatorial testing, factor covering array, oracle problem, t-way testing, verification and validation (V&V)


Kuhn, D. , Kacker, R. , Lei, Y. and Torres-Jimenez, J. (2015), Equivalence Class Verification and Oracle-Free Testing Using Two-layer Covering Arrays, 4th International Workshop on Combinatorial Testing, Vienna, -1, [online], (Accessed June 19, 2024)


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Created April 17, 2015, Updated November 10, 2018