The purpose of POSIWID is what it does

A response to Scott Alexander

A recent article by Scott Alexander has cast some doubt on the helpfulness of Stafford Beer’s well-known aphorism, ‘the purpose of a system is what it does’. (POSIWID for short.) Beer argued that systems – by implication therefore, schools – should be evaluated on their observable actions and results. A system’s real ‘purpose’ is revealed by consistently produced outcomes, regardless of what its designers or managers might claim.

Although at the level of human intentionality, it’s obviously absurd to claim that the purpose of a school is to produce poor outcomes for students, if that is what it consistently does, the intentions of those running it are functionally irrelevant. By focussing on what the system does rather than on what it should be doing, we have a better chance of addressing the discrepancies between stated aims and actual outcomes.

Scott observes that no one uses the axiom positively, (“Management Information Systems help schools manage data therefore the purpose of an MIS is to help schools manage data”) only negatively (“Using an MIS is stressful and confusing therefore the purpose of an MIS is to confuse and stress people out!”) Since this negative framing is obviously false (An MIS does help schools manage data, the stress and confusion are unfortunate byproducts) POSIWID is therefore at best redundant and at worst, obviously false.

The full Beer quote in which POSIWID first crops up is worth considering in full:

According to the cybernetician, the purpose of a system is what it does. This is a basic dictum. It stands for bald fact, which makes a better starting point in seeking understanding than the familiar attributions of good intentions, prejudices about expectations, moral judgment, or sheer ignorance of circumstances.

If you’re going to read this and conclude that Beer’s intention was that people should use POSIWID as a tool for asserting conspiracy theories then that would be as absurd as the conspiracy theorists’ claims. Obviously, Beer used – and wanted others to use – POSIWID as a tool for sidestepping stated intentions in order to interrogate the gap between aims and outcomes. My experience of confront people with the notion that the unintended consequences of their decisions are baked in to the systems they have designed and lead is that they are often startled out of complacency and willing to explore what tweaks and changes they can make to the feedback loops that might be generating these outcomes. Obviously, if I were to say that this was their fault, that they had nefariously designed in these unintended consequences, they’d be right to dismiss me as an antagonistic fool. The fact that it has never occurred to me to think this, let alone say it aloud has a lot to do with why I’ve found POSIWID useful.

But, if the purpose of POSIWID is what it does, and what it does, in many cases, is provide cover for loons to make mad claims about the world, then the only conclusion a budding cybernetician can draw is that the purpose of POSIWID is to produce conspiracy theories!

But, since the outcome of me using POSIWID is to prompt thoughtful conversations about how to improve schools, the purpose of POSIWID is to - obviously - prompt thoughtful conversations.