---
name: prototyping-concept-throwaway-evolutionary
description: 'Use this skill when picking which kind of prototype to build for the question at hand — concept (exploratory), throwaway (testing one specific aspect), or evolutionary (incremental toward final). Trigger when planning a research method, when scoping a technical spike, or when deciding whether an MVP should evolve or be thrown away. Sub-aspect of `prototyping`; read that first.'
---

# The three prototype kinds

The book identifies three prototype kinds — concept, throwaway, evolutionary — each with characteristic uses, costs, and failure modes.

## Concept prototypes

For exploring preliminary ideas. Quick, cheap, often disposable.

**Use for**: brainstorming sessions, early stakeholder alignment, exploring whether a direction is worth pursuing.

**Examples**: paper sketches, storyboards, mood boards, foam mockups, role-playing.

**Failure mode**: artificial reality problem. A skilled designer can make any concept look plausible; the prototype's polish doesn't predict actual workability.

## Throwaway prototypes

For testing specific aspects of a design.

**Use for**: performance benchmarks, A/B tests, single-flow user studies, technical spikes.

**Examples**: standalone interactive demos, wind-tunnel models, isolated code experiments.

**Failure mode**: scaling and integration problem. A throwaway that works in isolation may fail when integrated or at scale.

## Evolutionary prototypes

For incrementally building toward the final design.

**Use for**: MVPs that grow into products, iterative startup development, products with uncertain requirements.

**Examples**: software MVPs, agile sprint outputs, lean startup builds.

**Failure mode**: tunnel vision. Iterations refine the current direction; teams may miss fundamentally better directions.

## Picking the right kind

| Situation | Prototype kind |
|---|---|
| Exploring ideas; "is this worth doing?" | Concept |
| Testing one specific question | Throwaway |
| Iterating toward a final product | Evolutionary |
| Stakeholder alignment | Concept |
| Performance benchmark | Throwaway |
| Scaling a startup | Evolutionary |

The kinds aren't mutually exclusive. A typical project uses concept prototypes early (to align), throwaway prototypes mid (to test specifics), and evolutionary prototypes late (to ship and refine).

## Combining the kinds

A common pattern:

1. **Concept** prototypes to explore directions and align stakeholders.
2. **Throwaway** prototypes to test specific risks (performance, user flow, integration).
3. **Evolutionary** prototyping to build the actual product, informed by what concept and throwaway prototypes revealed.

Each kind catches different issues; using all three reduces the risk of any single failure mode.

## Resources

- Lidwell, Holden, Butler — *Universal Principles of Design* (2003).
- Schrage, M. *Serious Play* (1999).
- Brooks, F. *The Mythical Man-Month* (1995).
- Boehm, B. "A Spiral Model of Software Development and Enhancement" (1986).