Wisdom of crowds

"Wisdom of crowds" names the finding that the aggregate of many independent judgments — a median, a mean, a majority vote — can be more accurate than most or all of the individuals who produced it, traced back to Francis Galton's 1907 ox-weighing demonstration and popularized as a named concept by journalist James Surowiecki's 2004 book of the same title.

The concept matters to this vault as the backdrop against which Lorenz, Rauhut, Schweitzer & Helbing (2011) and Mavrodiev, Tessone & Schweitzer (2012) test the single condition that makes the effect fail: raters exposed to each other's estimates before finalizing their own, which the first paper names the "social influence effect." The effect's independence requirement is the same one Condorcet's 1785 jury theorem already formalizes on the vault's math-side cluster — this concept is the empirical, social-psychology-side cousin of that same independence condition, reached from a different literature.

References

• claim-lorenz-rauhut-schweitzer-helbing-2011-no-information-baseline-makes-convergence-diagnostic — convergence under social influence is diagnostic of an externally-anchored process, measured against a no-information baseline.
• claim-mavrodiev-tessone-schweitzer-2012-convergence-direction-depends-on-starting-population — that convergence's effect on accuracy depends on the population's starting diversity and accuracy, not on convergence itself.