Route
A route is the user's trajectory toward what they're trying to accomplish: the series of state-changes they move through to get from where they started to a state that counts as done. They assemble it step by step, drawing on whatever's at hand: parts of the product, tools they already use, things they improvise, help from people around them.
Definition
The user's trajectory through state-space — their series of state-changes en route to satisfying completion criteria.
Steps and state-changes
A route is the structural arc of the user's pursuit: the sequence of state-changes connecting their starting state to their resulting state. Each step changes the user's now-state, landing them somewhere new from which they take the next step. The route is the cumulative shape of that movement.
Users navigate routes by hopscotching across the affordance landscape — at each step, selecting which available affordance to incorporate based on what's reachable and route-efficacious at that moment. The trajectory includes affordances outside the provider's offering when those serve a step better than what the provider has built.
Route vs. path
The route belongs to the user. It's the trajectory the user traces through state-space in pursuit of their sought state. The path is the provider's deliberate route-efficacious affordances for a specific intent — the slice of the affordance landscape the provider has shaped. Multiple routes can cross the same path: different users from the same starting conditions make different selections at each step, producing different trajectories through the same designed affordances.
Path-shaping decisions are provider-side commitments; route success is user-side outcome. The provider shapes paths; the user traverses routes.
Critical route and actualized route
Critical route and actualized route are two senses of route that pick out different aspects of the trajectory.
The critical route is the minimum causal-dependency structure between selected endpoints — what any route bridging those starting and resulting conditions must satisfy. Given a specific pair of starting conditions and completion criteria, the critical route is singular: there is exactly one minimum-dependency map. It's the causal skeleton; any specific trajectory between those endpoints has to satisfy it.
The actualized route is the specific trajectory that unfolded for one user in one traversal — the cumulative trace of steps they made and executed. Where they actually went, what they hopscotched toward, what they hopscotched past, where they bypassed the offering's affordances entirely.
Route plurality
At coarse-grain completion criteria, multiple routes can satisfy the same resulting state. A user signing up for a project-management SaaS could reach "first project active" by creating a project from scratch, by importing from a spreadsheet, or by cloning a template. Each is its own route with its own critical route. Plurality emerges from inclusion-criteria granularity: at "first project active," all three serve; at "first project active from template," only one does. See route plurality.
Example
A new signup at a project-management SaaS arrives with the intent of getting their first project running. Their route from "signed up" to "first project active" might trace: dashboard → create project → name it → invite a collaborator → import a task list → confirm setup. Another user with the same starting conditions might route differently: dashboard → templates → pick a template → edit imported tasks → invite collaborator. Both produce the same resulting state through different sequences of hopscotches. The critical route — the causal dependency any traversal must satisfy — is something like: a project exists, the project has tasks, the project has at least one user. Each user's actualized route is the specific trace they leave through analytics.