Synthesis Quick Reference #

Evidence note: Any quantitative thresholds on this page are starter heuristics unless linked to the Evidence Ledger or a primary source + date. Calibrate by domain.

The Core Finding (in one sentence) #

Behavior selection determines outcomes more than execution quality.

Right behavior + mediocre execution beats wrong behavior + excellent execution.

The Behavior Fit Assessment (the three dimensions) #

Before you invest in solution design, screen candidate behaviors using the Behavior Fit Assessment.

The Behavior Fit Assessment is a practitioner decision tool for comparing candidate behaviors across Dispositional Fit, Capability Fit, and Context Fit. It is not a validated measurement instrument. Treat the minimum dimension as a bottleneck and prioritization heuristic; it is not a deterministic probability of behavior.

A score of 6 out of 10 on each Behavior Fit Assessment dimension is a starting threshold that must be calibrated by domain, population, context, stakes, and observed behavior.

Dispositional Fit #

Does this behavior match the population’s relatively enduring tendencies and preferences?

• High: The behavior draws on existing interests, values, preferences, characteristic priorities, and tolerances.
• Low: The behavior repeatedly demands tendencies or priorities that appear weak or uncommon in the target population.

“Identity Fit” is the legacy alternate name for this BFA dimension. Self-concept can be one signal in a specific case, but it does not define Dispositional Fit.

Capability Fit #

Can users actually perform this behavior in the real world?

• High: low skill requirement; first completion is easy for the median user.
• Low: requires sustained attention, special knowledge, physical ability, or complex setup.

Context Fit #

Does the environment support the behavior where it naturally occurs?

• High: the environment reliably triggers and enables repetition (tools, time, norms, infrastructure).
• Low: the environment blocks the behavior (time scarcity, stigma, interruptions, missing infrastructure).

The decision rules #

• Use a rating below the calibrated starting screen to identify a candidate bottleneck or evidence gap.
• Prioritize the behavior with the strongest minimum rating and clearest outcome path, then validate it through observation in realistic contexts.
• Execute via the DRIVE Framework, which maps directly to the Four-Fit Hierarchy.

The recurring patterns #

1. Match, don’t hack. The strongest strategies formalize and enable behaviors people already do (or already try to do).
2. Context > technology. Execution quality matters after fit is established.
3. Defaults are configuration, not magic. Defaults work best after behavior viability exists; they don’t create viability by themselves. See Why Nudges Fail.

Quick decision heuristic #

Next steps #

• Browse the Case Library to see how behavior selection predicts success and failure.
• Use the Behavior Fit Assessment Worksheet in your next Research sprint.