Skip to main content

Sweet Fifteen


What is the right number of tests? Which tester hasn't been asked that question many times in one form or another? When will the testing be done? Can you test to make sure this works? How much effort would it be to test that? Can you show that performance has improved? We need to shorten the run time of the automated tests, can you remove some? How many test cases are passing?

What is the right number of tests? According to Matalan, I found out over the Christmas holiday, the sweet spot appears to be fifteen:
We check our garments at least 15 times to ensure they meet your expectations on quality. 

Fifteen. It'd be easy to scoff, wouldn't it? Testing is never done, testing can never be complete, testing doesn't ensure anything, testing is brainwork, testing is an art, I tell you, it's an art!

Now, don't get me wrong: I love the theory, the philosophy, the abstract. I can be as up my own backside about testing as the next person. (And I am. I cite this blog as evidence.) But I also recognise that we work in a world where rubber, and risk, is constantly hitting the road. We are at the sharp end. The decisions we make under the constraints we have at any given time can matter. We also sometimes need to be able to provide genuine answers to questions like the ones at the top, when they're asked genuinely.

So I don't scoff (these days). I take the jarring statements and questions as an opportunity for a thought experiment. For example: what might be meant by the claim that Matalan are making? What real-world conditions could motivate the need to make such a claim? What kind of evidence could be used to back the claim up, were it ever challenged, and to what extent does that matter?

Which is why, while stalking round the store as my daughters hunted for new jumpers and a DVD to while away a couple of in-law hours that afternoon (after a family vote we ended up with The Pirates! In an Adventure with Scientists!) I found myself asking questions like these:
  • is the claim about every type of garment, regardless of its complexity? A sock gets the same attention as a three-piece suit?
  • is this a claim about some garments, some types of garment, every instance of a garment?
  • what are "our garments"? Those made by Matalan, those sold by Matalan, something else?
  • is it the same fifteen tests every time?
  • what even is a test of a garment? Are all tests equal? At all stages of manufacture, delivery, display, ...?
  • whose expectations are being satisfied?
  • who is likely to read this poster, on the outside of a store in a small out-of-town estate?
  • where else is the claim being made?
  • how is satisfaction being judged?
  • what is meant by quality? And how is it measured?
  • is the poster addressing a business need? Maybe potential customers are put off by perceptions of low quality?
  • is fifteen a marketing number based on data? Maybe in focus groups, people feel more confident with fifteen than fourteen or sixteen?
  • is fifteen, or perhaps the wording or phrasing, based on psychological research? Is the advert tuned to achieve its aim?
  • could a plausible number really be as low as fifteen, surely hundreds of checks are made during design, prototyping, trials, ...?
  • is this advert itself part of some A/B test? Are others seeing a different claim elsewhere?

Yes, yes, you say, very smart and all that, but what exactly does this kind of blathering achieve?

Fair point. For me, it serves as a reminder to stay humble, and also to think outside of the rails on which my thoughts might naturally run. There could be a bunch of reasons, a stack of context, assumptions, data, and belief behind a statement. Just because it doesn't fit you or me, given what we know, in the milliseconds it can take to form a reaction, doesn't mean it doesn't have a justification. There can be both sport and learning in taking the time to consider that.

I don't always remember, of course, and when I catch myself failing I think of Bob Marshall's definition of an idiot:
Anyone who is just trying to meet their needs, in the best way they know how, where their way makes little or no sense to us.
which I interpret as a call for "empathy first."

So, if you managed to endure what has turned out to be essentially a stream of consciousness this far down the page, and are right now wondering why on earth I bothered, let me just say there's at least fifteen reasons ...

Comments

Popular posts from this blog

Meet Me Halfway?

  The Association for Software Testing is crowd-sourcing a book,  Navigating the World as a Context-Driven Tester , which aims to provide  responses to common questions and statements about testing from a  context-driven perspective . It's being edited by  Lee Hawkins  who is  posing questions on  Twitter ,   LinkedIn , Mastodon , Slack , and the AST  mailing list  and then collating the replies, focusing on practice over theory. I've decided to  contribute  by answering briefly, and without a lot of editing or crafting, by imagining that I'm speaking to someone in software development who's acting in good faith, cares about their work and mine, but doesn't have much visibility of what testing can be. Perhaps you'd like to join me?   --00-- "Stop answering my questions with questions." Sure, I can do that. In return, please stop asking me questions so open to interpretation that any answ...

Can Code, Can't Code, Is Useful

The Association for Software Testing is crowd-sourcing a book,  Navigating the World as a Context-Driven Tester , which aims to provide  responses to common questions and statements about testing from a  context-driven perspective . It's being edited by  Lee Hawkins  who is  posing questions on  Twitter ,   LinkedIn , Mastodon , Slack , and the AST  mailing list  and then collating the replies, focusing on practice over theory. I've decided to  contribute  by answering briefly, and without a lot of editing or crafting, by imagining that I'm speaking to someone in software development who's acting in good faith, cares about their work and mine, but doesn't have much visibility of what testing can be. Perhaps you'd like to join me?   --00-- "If testers can’t code, they’re of no use to us" My first reaction is to wonder what you expect from your testers. I am immediately interested ...

The Best Programmer Dan Knows

  I was pairing with my friend Vernon at work last week, on a tool I've been developing. He was smiling broadly as I talked him through what I'd done because we've been here before. The tool facilitates a task that's time-consuming, inefficient, error-prone, tiresome, and important to get right. Vern knows that those kinds of factors trigger me to change or build something, and that's why he was struggling not to laugh out loud. He held himself together and asked a bunch of sensible questions about the need, the desired outcome, and the approach I'd taken. Then he mentioned a talk by Daniel Terhorst-North, called The Best Programmer I Know, and said that much of it paralleled what he sees me doing. It was my turn to laugh then, because I am not a good programmer, and I thought he knew that already. What I do accept, though, is that I am focussed on the value that programs can give, and getting some of that value as early as possible. He sent me a link to the ta...

Beginning Sketchnoting

In September 2017 I attended  Ian Johnson 's visual note-taking workshop at  DDD East Anglia . For the rest of the day I made sketchnotes, including during Karo Stoltzenburg 's talk on exploratory testing for developers  (sketch below), and since then I've been doing it on a regular basis. Karo recently asked whether I'd do a Team Eating (the Linguamatics brown bag lunch thing) on sketchnoting. I did, and this post captures some of what I said. Beginning sketchnoting, then. There's two sides to that: I still regard myself as a beginner at it, and today I'll give you some encouragement and some tips based on my experience, to begin sketchnoting for yourselves. I spend an enormous amount of time in situations where I find it helpful to take notes: testing, talking to colleagues about a problem, reading, 1-1 meetings, project meetings, workshops, conferences, and, and, and, and I could go on. I've long been interested in the approaches I've evol...

Not Strictly for the Birds

  One of my chores takes me outside early in the morning and, if I time it right, I get to hear a charming chorus of birdsong from the trees in the gardens down our road, a relaxing layered soundscape of tuneful calls, chatter, and chirrupping. Interestingly, although I can tell from the number and variety of trills that there must be a large number of birds around, they are tricky to spot. I have found that by staring loosely at something, such as the silhouette of a tree's crown against the slowly brightening sky, I see more birds out of the corner of my eye than if I scan to look for them. The reason seems to be that my peripheral vision picks up movement against the wider background that direct inspection can miss. An optometrist I am not, but I do find myself staring at data a great deal, seeking relationships, patterns, or gaps. I idly wondered whether, if I filled my visual field with data, I might be able to exploit my peripheral vision in that quest. I have a wide monito...

ChatGPTesters

The Association for Software Testing is crowd-sourcing a book,  Navigating the World as a Context-Driven Tester , which aims to provide  responses to common questions and statements about testing from a  context-driven perspective . It's being edited by  Lee Hawkins  who is  posing questions on  Twitter ,   LinkedIn , Mastodon , Slack , and the AST  mailing list  and then collating the replies, focusing on practice over theory. I've decided to  contribute  by answering briefly, and without a lot of editing or crafting, by imagining that I'm speaking to someone in software development who's acting in good faith, cares about their work and mine, but doesn't have much visibility of what testing can be. Perhaps you'd like to join me?   --00--  "Why don’t we replace the testers with AI?" We have a good relationship so I feel safe telling you that my instinctive reaction, as a member of the T...

Vanilla Flavour Testing

I have been pairing with a new developer colleague recently. In our last session he asked me "is this normal testing?" saying that he'd never seen anything like it anywhere else that he'd worked. We finished the task we were on and then chatted about his question for a few minutes. This is a short summary of what I said. I would describe myself as context-driven . I don't take the same approach to testing every time, except in a meta way. I try to understand the important questions, who they are important to, and what the constraints on the work are. With that knowledge I look for productive, pragmatic, ways to explore whatever we're looking at to uncover valuable information or find a way to move on. I write test notes as I work in a format that I have found to be useful to me, colleagues, and stakeholders. For me, the notes should clearly state the mission and give a tl;dr summary of the findings and I like them to be public while I'm working not just w...

Build Quality

  The Association for Software Testing is crowd-sourcing a book,  Navigating the World as a Context-Driven Tester , which aims to provide  responses to common questions and statements about testing from a  context-driven perspective . It's being edited by  Lee Hawkins  who is  posing questions on  Twitter ,   LinkedIn , Mastodon , Slack , and the AST  mailing list  and then collating the replies, focusing on practice over theory. I've decided to  contribute  by answering briefly, and without a lot of editing or crafting, by imagining that I'm speaking to someone in software development who's acting in good faith, cares about their work and mine, but doesn't have much visibility of what testing can be. Perhaps you'd like to join me?   --00-- "When the build is green, the product is of sufficient quality to release" An interesting take, and one I wouldn't agree with in gener...

Postman Curlections

My team has been building a new service over the last few months. Until recently all the data it needs has been ingested at startup and our focus has been on the logic that processes the data, architecture, and infrastructure. This week we introduced a couple of new endpoints that enable the creation (through an HTTP POST) and update (PUT) of the fundamental data type (we call it a definition ) that the service operates on. I picked up the task of smoke testing the first implementations. I started out by asking the system under test to show me what it can do by using Postman to submit requests and inspecting the results. It was the kinds of things you'd imagine, including: submit some definitions (of various structure, size, intent, name, identifiers, etc) resubmit the same definitions (identical, sharing keys, with variations, etc) retrieve the submitted definitions (using whatever endpoints exist to show some view of them) compare definitions I submitted fro...

Express, Listen, and Field

Last weekend I participated in the LLandegfan Exploratory Workshop on Testing (LLEWT) 2024, a peer conference in a small parish hall on Anglesey, north Wales. The topic was communication and I shared my sketchnotes and a mind map from the day a few days ago. This post summarises my experience report.  Express, Listen, and Field Just about the most hands-on, practical, and valuable training I have ever done was on assertiveness with a local Cambridge coach, Laura Dain . In it she introduced Express, Listen, and Field (ELF), distilled from her experience across many years in the women’s movement, business, and academia.  ELF: say your key message clearly and calmly, actively listen to the response, and then focus only on what is relevant to your needs. I blogged a little about it back in 2017 and I've been using it ever since. Assertiveness In a previous role, I was the manager of a test team and organised training for the whole ...