Framework · Measurement · Hooked
Measuring habit strength (SRHI and SRBAI)
Frequency is not habit. The four-item SRBAI measures automaticity directly (done automatically, without having to remember, without thinking, started before realizing) and correlates about .92 with the full 12-item SRHI. Survey users who did the behavior at days 7, 30 and 90, and pair it with unprompted share.
Plain label: self-reported automaticityAlso known as: SRBAI, SRHI, habit pulse, automaticity
Instruments. The SRHI has 12 items covering repetition, automaticity and identity; the SRBAI keeps its 4 automaticity items, with reliability mostly .80-.97 across 45 tests Evidence grade A. Robust evidence: replicated, peer-reviewed research.. F15 (How are habits formed: modelling habit formation in the real world, Lally et al., European Journal of Social Psychology, 2010)
Product habit pulse. Adapt the stem to the core value action (for example, "Checking my budget in [app] is something I..."), use a 7-point agreement scale and average the four items. Sample only users who did the action at least once.
Pair with behavior. Unprompted session share, time-of-day consistency and streak regularity. A habit means high automaticity in a stable context.
The bar. Hooked's rule of thumb is that at least about 5% of users should meet the habitual-frequency definition (benchmark confidence C; a book heuristic). HK-MEA03 (Hooked Ch.8)
Limits
What we don’t claim
- The Hook Model is a practical design tool, not a validated or complete theory of behavior.Hooked, Introduction
- Habit metrics need the longer habit horizon (weeks to months) before they can be read.
- The threshold is a heuristic, not a measured cut-off.
Sources
Hooked · Nir Eyal
Ch.8
Towards parsimony in habit measurement: the SRBAI · Gardner, Abraham, Lally and de Bruijn, IJBNPA 9:102, 2012
Evidence grade A. Robust evidence: replicated, peer-reviewed research.How are habits formed: modelling habit formation in the real world · Lally et al., European Journal of Social Psychology, 2010
Evidence grade B. Moderate evidence: solid studies with some limits.
Book content is paraphrased, never quoted at length. Last verified October 24, 2026.
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