Testing and Checking

In the first post in this series, I proposed “that those things that we usually call ‘unit tests‘ be called ‘unit checks‘.” I stand by the proposal, but I should clarify something important about it. See, it’s all a matter of timing. And, of course, sapience. After James Bach‘s blog post titled “Sapience and Blowing Peoples’ Minds“, Joe Rainsberger commented: Sadly, the distinction between testing and checking makes describing test-driven … Read more

In a previous comment, Sunjeet asks Does not testing encompass checking? Can testing alone be efficient without doing any checking? As I hope I made it clear in Elements of Testing and Checking, the development and analysis of checks is surrounded by plenty of testing activity, and testing may include a good deal of checking. Testing, I think, can be vastly more efficient if we consider the ways in which … Read more

The word “criticism” has several meanings and connotations. To criticize, these days, often means to speak reproachfully of someone or something, but criticism isn’t always disparaging. Way, way back when, I studied English literature, and read the work of many critics. Literary critics and film critics aren’t people who merely criticize, as we use the word in common parlance. Instead, the role of the critic is to contextualize—to observe and … Read more

In the course of trying to describe distinctions between testing and checking, a number of questions have come up: Do you want to change the language? Won’t saying “check” be confusing? Won’t this undermine our goal of industry-standard terminology? Won’t calling certain kinds of tests “checks” fly in the face of years of documentation and books? Isn’t this yet another case of you wanting testing to be done the same … Read more

In the last couple of weeks, I’ve been very gratified by the response to the testing-vs.-checking distinction. Thanks to all who have grabbed on to the idea and to those who have questioned it. There’s a wonderful passage in Chapter 4 of Jerry Weinberg‘s Perfect Software and Other Illusions About Testing in which he breaks down the activities of a programmer engaged in testing activities—testing for discovery, discovering an unexpected … Read more

A test, for the purposes of this discussion, is at its core a process of exploration. Initially, our community described exploratory testing as “simultaneous test design, test execution, and learning.” Later descriptions included “simultaneous test design, test execution, and learning, with an emphasis on learning“, “a parallel process of test design, test execution, test result interpretation, and learning, with an emphasis on learning”. At the Workshop on Heuristic and Exploratory … Read more

James Bach and I have a thing that we do called “transpection“. It’s not at all new (you do it, Socrates and his interlocutors did it in Plato’s dialogs, and people did it long before that and have done it ever since) but I think James’ word for it is new. Transpection is an exploratory conversation aimed (or chartered) towards discussing and refining a particular idea. Transpection is a way … Read more

Post-postscript: Think of this blog post with its feet up, enjoying a relaxing retirement after a strenuous career. Please read the new version first. In the years since the original post, I’ve further refined my take on the subject of testing and checking, mostly in collaboration with my colleague James Bach. Our current thinking on the topic appears on his blog, and I provide some followup here. We’ve also benefitted … Read more