Skip to main content

Isn't It Obvious?

You've almost certainly heard of the Prisoner's Dilemma: two members of a crimimal gang are captured and interrogated separately. The police tell them both they are looking at a year in prison but offer a deal if they squeal: less time for incriminating their colleague. There are three scenarios:

  • No-one talks: the default one year each
  • One talks: the talker goes free, the other gets three years
  • Both talk: both get two years 

The dilemma is whether to remain shtum and trust the other will do the same or to spill the beans with the risk of an extended stay in prison but the potential reward of walking away scot free. 

Given that they are sure the other would be prepared to rat them out, the rational individual's strategy, according to game theory, is to talk even though there is a better group outcome in not talking.

--00-- 

The Prisoner's Dilemma is merely a well-known example but there are many other games with different setups and constraints. I came across one recently, the coordination game, that I think is interesting from a software development perspective.

In a simple coordination game there are again two players and they must again make an independent decision but in this scenario they are rewarded only when they choose the same option. The idea was introduced in a recent episode of the Cautionary Tales podcast like this:

In his 1960 book, The Strategy of Conflict, the game theorist Thomas Schelling asks us to imagine a couple who lose each other in a department store. It's the 1960s so they can't just call, but the chances are good, says Schelling, that they'll find each other. They'll each think of some obvious place to meet that will obviously be obvious to the other.  

The question, he says, is not "what would I do if I were she?", but "what would I do if I were she, wondering what she would do if she were I, wondering what I would do if I were she?"

--00--

Four years ago, in a post not dissimilar to this one, I wrote about boundary objects. A boundary object is something that sits between two collaborating groups and serves as a way of documenting a shared aim, constraints, or knowledge. It needs to be accessible to, agreed upon, and understandable by, everyone whose boundaries they lie on, but each group will use them differently. 

In our software world, examples of boundary objects might be Jira tickets (product manager and developers), Figma wireframes (designers and implementation teams), or unit tests (today's developers and tomorrow's).

--00--

Many teams these days, and mine is one, are distributed geographically and temporally but, even in teams that are colocated, the truth is that much communication about work is asynchronous or non-existent. A boundary object serves as an anchor for work when synchronous communication doesn't happen, a place where we can align our mental models.

Until today, I hadn't considered that there's a kind of coordination game being played around the boundary object: we aren't just trying to finish our tasks, we are trying to ensure that my piece fits your piece without us having to talk about it.

A twist in the software development context is that, unlike the department store, the ground is constantly shifting. A developer might discover a technical blocker or a stakeholder might tweak a requirement and suddenly the "obvious" meeting point is in the sports department in the basement, not the cafe on the top floor.

In this kind of scenario, the challenge becomes one of keeping the boundary object up to date enough to allow the coordination game to be played efficiently by all parties. When you're asking "what would I do if I were she, wondering what she would do if she were I, wondering what I would do if I were she?" you will do better when both of you to have access to the same recent version of a shared model.

--00-- 

It's worth noting that boundary objects are not the only way to approach a coordination problem either. For example, agile methodologies which break work down into smaller pieces and iterate quickly through a plan-do-check-act cycle lower the stakes of divergent models by moving as a group: in the department store metaphor perhaps we'll stay in the same department and keep an eye on each other.

I'm not telling you something you didn't already know implicitly, I'm sure, but I find it interesting to have names for and theory about this kind of thing. It helps to explain why some of our colleagues think a ticket with title "implement the thing" is enough for a week's worth of work while others will write a three-page specification document focussed just on the user experience of that thing.

For me, keeping a boundary object sufficiently in step with the world is less about housekeeping and more mapmaking. I don't want a coordination game to turn into a dilemma, so I prioritise sharing but I also think carefully about how much effort to invest because people have different needs and different opinions on what "should" "just" be "obvious."

And I'm sure you feel the same way about that.
Image: Sangga Rima Roman Selia on Unsplash

Labels:

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...
Read more

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 ...
Read more

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...
Read more

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...
Read more

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...
Read more

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...
Read more

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...
Read more

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...
Read more

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...
Read more

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...
Read more