Smoke Testing vs. Sanity Testing: What You Really Need to Know

If you spend any time in forums in which new testers can be found, it won’t be long before someone asks “”What is the difference between smoke testing and sanity testing?” “What is the difference between smoke testing and sanity testing?” is a unicorn question. That is, it’s a question that shouldn’t be answered except perhaps by questioning the question: Why does it matter to you? Who’s asking you? What … Read more


Several years ago, I worked for a few weeks as a tester on a big retail project. The project was spectacularly mismanaged, already a year behind schedule by the time I arrived. Just before I left, the oft-revised target date slipped by another three months. Three months later, the project was deployed, then pulled out of production for another six months to be fixed. Project managers and a CIO, among … Read more

Testing: Difficult or Time-Consuming?

In my recent blog post, Testing Problems Are Test Results, I noted a question that we might ask about people’s perceptions of testing itself: Does someone perceive testing to be difficult or time-consuming? Who? What’s the basis for that perception? What assumptions underlie it? The answer to that question may provide important clues to the way people think about testing, which in turn influences the cost and value of testing. … Read more

Testing Problems Are Test Results

I often do an exercise in the Rapid Software Testing class in which I ask people to catalog things that, for them, make testing harder or slower. Their lists fit a pattern I hear over and over from testers (you can see an example of the pattern in this recent question on Stack Exchange). Typical points include: I’m a tester working alone with several programmers (or one of a handful … Read more

Can You Test a Clock in a Sealed Box?

A while ago, James Bach and I did a transpection session. The object of the conversation was to think critically about the common trope that every test consists of at least an input and an expected result. We wanted to go deeper than that, and in the process we discovered a number of useful ideas. A test can be informed by an expectation, but oracles can also be developed on … Read more

I Reject His Argument: A Buffet of Logical Fallacies

Testing is about not being fooled, and being fooled often starts with fooling yourself. A while back on Twitter, I posted some of these little examples of problems in argumentation, most of which include some logical fallacy or another. It’s a fun game; add your own! I reject his argument because 73.154% of the time, he uses misleadingly precise data. I reject his argument because he’s appealing to authority, and … Read more

The Undefinition of “Done”

Recently a colleague noted that his Agile team was having trouble with the notion of done. “Sometimes it seems like the rest of the team doesn’t get it. The testers know that ‘done’ means tested. And if you ask the programmers, they’ll acknowledge that, yes, done means tested. Everyone is acting in good faith. But during the sprint planning meeting, we keep having to remind people to include time and … Read more

Common Languages Ain’t So Common

A friend told me about a payment system he worked on once. In the system models (and in the source code), the person sending notification of a pending payment was the payer. The person who got that notice was called the payee. That person could designate somone else—the recipient—to pick up the money. The transfer agent would credit the account of the recipient, and debit the account of the person … Read more

Exploratory Testing is All Around You

I regularly converse with people who say they want to introduce exploratory testing in their organization. They say that up until now, they’ve only used a scripted approach. I reply that exploratory testing is already going on all the time at your organization.  It’s just that no one notices, perhaps because they call it “review”, or “designing scripts”, or “getting ready to test”, or “investigating a bug”, or “working around … Read more

“Flawed” Analogies

Note: This post contains plagiarism: I’ve stolen some content from an earlier blog post, and from my comments on another. I beg the forgiveness of faithful and diligent readers. Recently I’ve had to deal with some complaints from people on Twitter who seem to have misinterpreted certain analogies. Worse than that, sometimes it seems as though they don’t understand why and how we use analogies at all. Here are some … Read more