Skip to main content

Dishing the Dirt


The four presentations at CEWT #7 were on the topic of Dirty Testing Secrets. Here's my brief summary.

According to Karo Stoltzenburg, we testers have a bad case of hubris about the uniqueness and value of our work. Not to put too fine a point on it, half of what we do is pointless and in any case could be done by someone else. Testers, she says, pride themselves on questioning, communicating and facilitating communication, and finding the important bugs but really they should find a bit of time to take a long, hard look at themselves.

Questions? She's heard better from developers, subject matter experts, product owners. Testers have no monopoly on critical thinking and people in other roles have information and experience to bring to the table that testers often won't. Communication? Sure, it's common for testers to bring people together but we're also often then an extra node in the information flow network, a contributor to the cacophony of Chinese whispers rattling round any org. And bugs? Pah, who cares that there's 37 different edge cases three levels down in some barely used dialog? Great creativity on your colour-coded mind map of a zillion test cases, oh wise testing master, but which paths through the product do users actually care about?

The resulting discussion ranged wide, covering the value of connecting other people and then perhaps dropping out, the need to keep at least one eye on the big picture, exploratory testing as a core skill of testers, not blocking others from testing, the trade off between reporting all the things and not reporting something that turns out important, teams owning quality, and the outcome for the customer being paramount. (Blog post.)

There's a famous quote in marketing, attributed to John Wannamaker: "Half the money I spend on advertising is wasted; the trouble is I don't know which half."  How could we know in advance which half of the testing not to do? I asked a similar question a few years ago: testing can’t find all the bugs, so which ones shouldn’t we look for?

You can't get to know what testing is without doing it. That's the dirty secret at the heart of Sime Simic's talk. A tester new to testing starts from a very low base, with many questions to answer about the product, the environment, the company, the users, the sales proposition, their team ... and themselves. The irony is that an experienced tester on a new project, or product, or moving to a new company has many of the same questions.

Sure, the old hand will have some experience, but they also have the extra layer of complication that they don't know which pieces of that are relevant to the new role. How can a tester get credibility and respect, learn to trade cost and value, be efficient, be effective? Only by doing and reflecting, and not rushing to get there.

Again, the conversation flowed, this time passing through getting feedback to understand how others see you and your work, building relationships with developers (particularly), the need to raise interesting things to people who matter, outcomes rather than outputs in spite of pressure to produce the latter, using the flexibility that the tester role permits to go to where the value can be found, and the granularity effect on value: how high value to a company can be low to a team or an individual.

Mark Bunce's experience report described joining a project to implement crucial business logic with a mixture of rule-based and machine learning technology. When Mark came on board the system was biased in favour of the machine learning component and performance, in terms of both accuracy and speed, was poor. There were no testers.

He built up a test team and broke down the work the system was doing to see just where the machine learning was actually adding value and where rules could do better. Testers are certainly not the only people who can apply critical thinking, but they sure helped on this project where performance is now dramatically better and the proportion of logic implemented by machine learning is dramatically lower.

After Mark's talk we dove into details of the particular system and the crude but effective statistical analysis that helped to show where the holes were. We wondered about the quantity and representativeness of the test data sets used to exercise systems like this. Random selections of deidentified production data is good, but can't be the whole story; people still need to look at the system and the outputs it produces. Another interesting angle was the ethical question of getting subject matter experts to train a machine learning system that is designed to replace them. What motivation do they have to help it to do a good job?

My own talk is written up in We Don't Know?

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...

How do I Test AI?

  Recently a few people have asked me how I test AI. I'm happy to share my experiences, but I frame the question more broadly, perhaps something like this: what kinds of things do I consider when testing systems with artificial intelligence components .  I freestyled liberally the first time I answered but when the question came up again I thought I'd write a few bullets to help me remember key things. This post is the latest iteration of that list. Caveats: I'm not an expert; what you see below is a reminder of things to pick up on during conversations so it's quite minimal; it's also messy; it's absolutely not a guide or a set of best practices; each point should be applied in context; the categories are very rough; it's certainly not complete.  Also note that I work with teams who really know what they're doing on the domain, tech, and medical safety fronts and some of the things listed here are things they'd typically do some or all of. Testing ...

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...

Notes on Testing Notes

Ben Dowen pinged me and others on Twitter last week , asking for "a nice concise resource to link to for a blog post - about taking good Testing notes." I didn't have one so I thought I'd write a few words on how I'm doing it at the moment for my work at Ada Health, alongside Ben. You may have read previously that I use a script to upload Markdown-based text files to Confluence . Here's the template that I start from: # Date + Title # Mission # Summary WIP! # Notes Then I fill out what I plan to do. The Mission can be as high or low level as I want it to be. Sometimes, if deeper context might be valuable I'll add a Background subsection to it. I don't fill in the Summary section until the end. It's a high-level overview of what I did, what I found, risks identified, value provided, and so on. Between the Mission and Summary I hope that a reader can see what I initially intended and what actually...

On Herding Cats

Last night I was at the Cambridge Tester meetup for a workshop on leadership. It was a two-parter with Drew Pontikis facilitating conversation about workplace scenarios followed by an AMA with a group of experienced managers. I can't come to work this week, my cat died. Drew opened by asking us what our first thoughts would be as managers on seeing that sentence. Naturally, sadness and sympathy,  followed by a week ? for a cat ? and I only got a day for my gran! Then practicalities such as maybe there's company policy that covers that , and then the acknowledgement that it's contextual: perhaps this was a long-time emotional support animal . Having established that management decisions are a mixture of emotion, logic, and contingency Drew noted that most of us don't get training in management or leadership then split us into small groups and confronted us with three situations to talk through: Setting personal development goals for others. Dropping a clange...

Reasonable Doubt

In Your job is to deliver code you have proven to work  Simon Willison writes: As software engineers we ... need to deliver code that works — and we need to include proof that it works as well.  He is coming at this from the perspective of LLM-assisted coding, but most of what he says applies in general. I think this is a reasonable consise summary of his requirements for developers: Manual happy paths: get the system into an initial state, exercise the code, check that it has the desired effect on the state. Manual edge cases: no advice given, just a note that skill here is a sign of a senior engineer.  Automated tests: should demonstrate the change like Manual happy paths  but also fail if the change is reverted.  He notes that, even though LLM tooling can write automated tests, it's humans who are accountable for the code and it's on us to "include evidence that it works as it should." Coincidentally, just the week before I read his post I told one of my...

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...

Why Test, Test What, Then How?

There was a time when testing was all about the mnemonics . Well, we had no AI back then so thinking about our human craft and how to share what we had learned using our human intelligence with other engaged humans for later recall in their human heads seemed important. But this post isn't about dumping on AI. It isn't about mnemonics either even if WTTWTH does look like something that'd fit well into that ancient world.  No, this post is just a snappier version of what I said to my team this week when I was walking through some testing I'd done the day before. It was concerned with a change to a particular turn in the dialog system we're building where multiple variables are in play, some populated by an external call to an LLM service.  I wanted to make the point that the bulk of the testing work was done in the research I did and the spreadsheet I made, not in the interaction with our product. That spreadsheet was the result of me looking in our service's cod...

Open Your Mind

Jerome Groopman, in How Doctors Think , reviews ways in which doctors can make poor choices, identifies potential causes, and suggests some practices, for both doctor and patient, that can help to prevent them. I find this interesting for a couple of reasons: first, I work in the health space, although not in a therapeutic area and, second, I like to reflect on my own thought processes. I'll take three broad themes from Groopman's analysis: the business of healthcare and how that impacts a physician's ability to practice; the doctor-patient relationship and how that impacts the experience of both sides; and the cognitive failings that impact a correct and timely diagnosis for any given patient. Naturally, these overlap. The book is written from the perspective of the notoriously commercialised American medical system and is around 20 years old, so doubtless some of the details are different outside of the US and have changed since pu...

Better Isolate Than Never

How do you test a product with distributed logic and non-deterministic components? Well, it depends on the product and when the question is asked. This post is one answer, for now. A service I work on exposes an API for internal and external clients and calls multiple other services. It orchestrates a reasonably complex journey for a user, with their inputs and the responses of the services determining each step.  Our customers can configure the service to provide a variant of the standard journey for their users. This gives them choices on the available steps, the order of the steps, and, importantly, some of the logic for taking particular steps. This configuration lives in a different repository to the service, not owned by us, and it can be changed and deployed independently from the service. As you can imagine, we test our service in multiple ways at different granularities using the usual tooling, including unit tests fo...