Curious about what’s going on behind the scenes with verification? Bernard Murphy, Jim Hogan, and our own Paul Cunningham are on the case with the “Innovation in Verification” blog stream over at semiwiki.com. Every month, this trio reviews a newly-published paper in academia that pertains to verification and discusses its implications. Be sure to stop by—it’s a great place to see what might be coming down the pipeline someday.

This month, they discuss the implications of metamorphic testing. The purpose of metamorphic testing is to define a verification approach where is there is no “golden reference.” This situation comes up a lot now as designs grow in complexity, and it begs the question: “how does one know the design is verified if there is no standard to compare to?”. Metamorphic testing addresses the problem of not having a “gold standard” to compare to by comparing the results of related tests instead. The paper reviewed by this team used metamorphic testing to study methods of managing JavaScript tags.

Paul saw this as a valuable new class of coverage. Metamorphic testing represents a way to create better distribution analyses through understanding the relationships among tests. This can reveal critical-but-complex issues that traditional verification methods may overlook. He saw this as an emerging class of coverage that new verification tools could be built around. Paul asserted that a future metamorphic-testing-based tool’s main contribution to the field of verification would be to better analyze noisy performance results where the noise is multi-modal. It could be useful in detecting race conditions and similar hard-to-debug anomalies. Paul also sees metamorphic testing as ripe for ML techniques. Overall—Paul sees a bright future for metamorphic testing in verification.

Jim is reminded of Solido and Spice—these metamorphic testing capabilities are “more than just a feature”—they might be a product. Maybe even a whole new class of verification tools, as Paul said.

Bernard says that this topic is “too rich to address in one blog”, so be sure to head over to the post to see more of what the future has in store for verification.