How do people use a software product? Some development groups model use through use cases. Typically use cases are expressed in terms of the user performing a set of step-by-step behaviours: 1, then 2, then 3, then 4, then 5. In those groups, testers may create test cases that map directly onto the use cases. Sometimes, that gets called a scenario, and the testing of it is called a scenario … Read more
“Computers and their software are two things. As collections of interacting cogs they must be ‘checked’ to make sure there are no missing teeth and the wheels spin together nicely. Machines are also ‘social prostheses’, fitting into social life where a human once fitted. It is a characteristic of medical prostheses, like replacement hearts, that they do not do exactly the same job as the thing they replace; the surrounding … Read more
If you’ve been in testing for long enough, you’ll eventually report or demonstrate a problem, and you’ll hear this: “No user would ever do that.” Translated into English, that means “No user that I’ve thought of, and that I like, would do that on purpose, or in a way that I’ve imagined.” So here are a few ideas that might help to spur imagination. The user made a simple mistake, … Read more
In the previous post, Lynn McKee recognized that, with respect to the Comparable Product oracle heuristic, “comparable” can be have several expansive interpretations, and not just one narrow one. I’ll emphasize: “comparable product”, in the context of the FEW HICCUPPS oracle heuristics, can mean any software product, any attribute of a software product, or even attributes of non-software products that we could use as a basis for comparison. (Since “comparable … Read more
People interpret requirements and specifications in different ways, based on their models, and their past experiences, and their current context. When they hear or read something, many people tend to choose an interpretation that is familiar to them, which may close off their thinking about other possible interpretations. That’s not a big problem in simple, stable systems. It’s a bigger problem in software development. The problems we’re trying to solve … Read more
It had been a long day, so a few of the fellows from the class agreed to meet a restaurant downtown. The main courses had been cleared off the table, some beer had been delivered, and we were waiting for dessert. Pedro (not his real name) was complaining, again, about how much time he had to spend doing administrivial tasks—meetings, filling out forms, time sheets, requisitions, and the like. “Everything … Read more
Over the last few years, people have become increasingly enthusiastic about the idea of mind mapping to help them describe or illustrate or otherwise consider test coverage. For me, Darren McMillan was the one who really got the ball rolling here, here, and here. More recently there have been other examples to present coverage ideas. Colleague Adam Goucher has weighed in here. But there’s another thing you can do, something … Read more
Several years ago, I wrote an article for Better Software Magazine called Testing Without a Map. The article was about identifying and applying oracles, and it listed several dimensions of consistency by which we might find or describe problems in the product. The original list came from James Bach. Testers often say that they recognize a problem when the product doesn’t “meet expectations”. But that seems empty to me; a … Read more
In which the conversation about heuristics and oracles continues… Tony’s brow furrowed as he spoke. “No oracle comes with a guarantee that it’s giving you the right answer. That’s what you said. But surely there are some oracles that are reliable,” he said. “What about pure math?” “Pure math? All right. Here’s an example: what’s 61 plus 45?” “Duh. 106.” “Well,” I said, “for many computer systems prior to the … Read more
In which the conversation about heuristics and oracles continues… “So what’s the difference,” I asked my tester friend Tony, “between an oracle and a heuristic?” “Hmm. Well, I’ve read the Rapid Testing stuff, and you and James keep saying an oracle is a principle or mechanism by which we recognize a problem.“ “Yes,” I said. “That’s what we call an oracle. What’s the difference between that and a heuristic?” “An … Read more