Are Test Oracles a mathematical nicety to cover-up problems?

Last week I had an interesting discussion with a colleague that did not agree with my take on Model-Based Testing. He was unwilling to buy my arguments for why Model-Based Testing is a more efficient way of automating test cases compared to traditional scenario automation. He was a firm believer in Model-Based Testing but his experiences told him that modeling was an expensive cost up-front, which could be made up for in maintenance savings, whereas I claimed that modeling was a much cheaper automation approach.

Furthermore, he argued that my model was close to useless, because it did not come with a validation oracle. At a deeper level, the discussion also revealed some interesting discrepancies to me: He believed.

Needless to say, we never reached agreement on the subject – but I realized later on that we were arguing from completely different perspectives.

After the discussion I started thinking: “How can we be of so differing opinions?” After fumbling around with this question in my head over the weekend, I realized that we were using Model-Based Testing for two completely separate purposes.

A notion started to form in my head – it seemed that there were different ‘schools’ (or views) within Model-Based Testing.

·         Theoretical modelers: They want strict rules around their models, and conduct rigorous validation in an effort to validate the conformity of their models. They have a theoretical approach to software testing and like to mathematically prove algorithms and construct test cases that cover just the necessary and sufficient cases.

·         Pragmatic modelers: They are more of the ad-hoc modeling type. They have a pragmatic approach to Model-Based Testing in which a model is valuable on its own. They understand that the model should be validated, but they can live with limited validations. They see value in the model as a means for communication.