Experiment Iteration Loop

The experiment iteration loop is the disciplined cycle of preparing hypotheses, running tests, interpreting losses or wins, and moving into the next evidence-based iteration.

Key points

• Statsig recommends writing the next hypothesis before launching the current test, so teams can act faster and more logically if the current idea fails ^[src-030].
• The guide recommends a "why might this fail?" pre-mortem before launch to surface blind spots and create useful future iterations ^[src-030].
• Teams should avoid declaring defeat too early because some winning tests can look weak at the start; the article recommends setting a losing threshold and using analysts to calm premature reactions ^[src-030].
• After a losing result, the next iteration should still be hypothesis-led rather than an anxious attempt to "do something" ^[src-030].
• Winning is not the end of the loop: the guide recommends testing again after a green result because the first win often reveals the next improvement opportunity ^[src-030].
• The loop depends on clear organizational processes for research, monitoring, iteration, and decision-making so testing becomes repeatable rather than heroic ^[src-030].
• Statsig's enterprise-scale article raises the bar for large programs: every test should begin with a falsifiable hypothesis and end with post-test synthesis that feeds a central archive ^[src-036].
• At scale, the next cohort of ideas should reference prior evidence, so experiments compound into cumulative learning instead of isolated coin flips ^[src-036].

Related entities

• Statsig

Related concepts

• Ab Testing Mindset
• Experiment Statistical Power
• Parallel Ab Testing
• Ab Testing Vs Bandits
• Enterprise Scale Experimentation
• Experiment Coverage
• Overall Evaluation Criterion

Source references

• ^[src-030] Israel Ben Baruch — "Move forward: The A/B testing mindset guide" (2025-06-16)
• ^[src-036] Yuzheng Sun — "Addressing complexity in enterprise-scale experimentation" (2025-04-23)