R6 — When variable/uncertain feedback is appropriate, cite Shen-Fishbach-Hsee (benign motivating-uncertainty, process focus, immediate resolution) — NOT Skinner box; respect the dark-pattern caveat

Rule: When variable / uncertain feedback is used in a tool design, cite the benign motivating-uncertainty literature (Shen, Fishbach & Hsee (2015), JCR 41(5) — Motivating-Uncertainty Effect: people invest MORE effort for an uncertain reward (50% $2 / 50% $1) than for certain HIGHER-expected-value reward — but ONLY under PROCESS focus, Shen, Hsee & Talloen (2019), JCR 46(1) — uncertain incentives reinforce REPETITION decisions (lab + field stair-climbing) — but only if uncertainty resolves IMMEDIATELY and only AFTER engagement begins) — NOT Ferster & Skinner (Ferster & Skinner (1957), Schedules of Reinforcement — variable-ratio (VR) schedules produce highest, steadiest response rates and strong resistance to extinction) or Schultz primate electrophysiology (Schultz, Dayan & Montague (1997), Science 275 — reward-prediction-error signal: unpredicted rewards drive dopamine bursts; fully predicted ones don't; primate electrophysiology). Respect the process-focus + immediate-resolution conditions. Treat the mechanism as conditional and ethics-flagged.

Why: The classic VR-schedule literature is dominantly a gambling / compulsion literature (Skinner himself (1953, Science and Human Behavior) — VR's power illustrated via GAMBLING: "the efficacy of such schedules in generating high rates has long been known to the proprietors of gambling establishments"). Citing Skinner for benign tool engagement is a stretch the schedule literature does not support. Shen-Fishbach-Hsee provides the only clean benign evidence — real rewards, normal adults, controlled experiments — but it requires process focus and immediate uncertainty resolution to work; under outcome focus it reverses to uncertainty aversion.

How to apply:

• Use variable / uncertain elements sparingly and ethically — never as a manipulative engagement crutch.
• Frame the user's focus on process ("explore your options"), not outcome ("win the bigger prize").
• Resolve any uncertainty immediately — variable rewards that take time to resolve frustrate rather than engage.
• If a design starts looking slot-machine-shaped, kill it.