Theory and Practice Case Files
Series 1: Theory of Change and Mind
Theory of Change and Mind Tuesday 29th September 2026 Case notes 01 - When our theory meets people. Imagine a service designed around a simple assumption: If we make support available, people will use it. It sounds reasonable. But what if the person we designed it for: • doesn't trust the organisation • has had a poor experience before • finds the process overwhelming • is worried about what asking for help might mean • doesn't recognise themselves in the language we use • is simply too cognitively overloaded to take the next step? The activity hasn't necessarily ‘failed’. Our theory about what would enable the behaviour may have been incomplete. This is where the intersection of Theory of Change X Theory of Mind can be so interesting together. The Theory of Change asks: What do we think will cause change? The mind asks: What might the person actually be thinking, feeling, and experiencing? And practice gives us another great question - What did reality teach us that our original theory missed? That really give us an opportunity for a practice-to-theory learning loop.
The Theory and Practice Casefiles - Theory of Change and Mind, Case File #02 The mental model hiding in the room. A service has a problem with missed appointments. The theory seems straightforward: People miss appointments because they forget, disengage or aren't motivated enough. So, the response is reminders. Better communications. Perhaps an incentive. But then co-design happens. People describe juggling work, caring responsibilities, unpredictable transport, previous experiences of judgement, anxiety about attending, and several services competing for their attention. The problem starts to look rather different. The intervention wasn't necessarily wrong. The mental model behind it may have been incomplete. This is one of the reasons the intersection of Theory of Change and Mind can be so helpful. A Theory of Change makes our causal assumptions more visible. A Theory of Mind encourages us to become curious about the assumptions we make about what people think, feel, know, and believe. And practice gives us the opportunity to challenge both. This is where systemic service design can become particularly powerful: Don't just design around the behaviour you observe. Get curious about the thinking, context and system that might be producing it. The Case File Question that I’ve been exploring this week: What mental model about people or behaviour is currently shaping your Theory of Change, and what evidence might challenge it?
