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DebunkedThe PolygraphThe instrument popularly called a lie detector, which records breathing, blood pressure, pulse and skin conductance dur…

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The library

Capsules

1,028 capsules, each one classified by the strength of its evidence.

All1,028Fact599Proven130Theory89Hypothesis71Contested90Debunked48
geography236biology88physics67history54medicine45astronomy33psychology26mathematics26chemistry20engineering20astrophysics19neuroscience19anthropology18art18
Filtered bystatisticsClear all

Results

Showing 1 to 19 of 19

NewestMost votedA to Z
Fact

Medical Screening

Testing people without symptoms to detect disease early. It saves lives in specific programmes and causes harm in others, and distinguishing between…

byCapsule
0 votes0 reviews
Aug 5, 2026
Fact

Probability

The mathematics of uncertainty. It assigns numbers between zero and one to events, and its rules are simple enough to state on a page and produce…

byCapsule0 votes0 reviewsAug 5, 2026
Fact

Correlation

A statistical measure of how far two variables move together. It is among the most widely used quantities in research and among the most widely…

byCapsule0 votes0 reviewsAug 5, 2026
Fact

Sampling

Selecting part of a population in order to draw conclusions about the whole. It is what makes measurement of large populations possible, and how the…

byCapsule0 votes0 reviewsAug 5, 2026
Fact

The Normal Distribution

The symmetric bell-shaped probability distribution that arises whenever many small independent influences add together. It is the most important…

byCapsule0 votes0 reviewsAug 5, 2026
Fact

The Census

A count of a population, conducted by a state, at a defined moment. It is among the oldest functions of government and remains the foundation on…

byCapsule0 votes0 reviewsAug 5, 2026
Theory

Signal Detection Theory

The framework that separates how well an observer can distinguish signal from noise from how willing that observer is to say the signal is present.…

byCapsule0 votes0 reviewsAug 4, 2026
Proven

The Two-Hit Hypothesis

Cancer caused by loss of a tumour suppressor requires both copies of the gene to be knocked out. Alfred Knudson deduced this in 1971 from the…

byCapsule0 votes0 reviewsAug 4, 2026
Proven

Bayes' Theorem

A rule for updating a belief when new evidence arrives. It is a short piece of algebra, it is not in any dispute, and misapplying it produces some of…

byCapsule0 votes0 reviewsAug 3, 2026
Proven

The Randomised Controlled Trial

Assign people to treatments by chance, and the groups differ only by chance. It is a simple idea, it is the most reliable method medicine has for…

byCapsule0 votes0 reviewsAug 3, 2026
Contested

The Flynn Effect

Average scores on intelligence tests rose steadily throughout the twentieth century, by roughly three points per decade in the countries with long…

byCapsule0 votes0 reviewsAug 3, 2026
Contested

The Great Crime Decline

Violent crime fell steeply across most of the developed world from the early 1990s, in some countries by more than half. The fall is one of the best…

byCapsule0 votes0 reviewsAug 3, 2026
Contested

The Replication Crisis

The replication crisis is the finding that a substantial share of published research results cannot be reproduced when the studies are repeated. It…

byCapsule0 votes0 reviewsAug 3, 2026
Proven· Mathematical Proof

Regression to the Mean

Regression to the mean is the tendency for an extreme measurement to be followed by one closer to average, for no reason other than that extremes…

byCapsule0 votes0 reviewsAug 3, 2026
Proven· Mathematical Proof

Simpson's Paradox

Simpson's paradox is the phenomenon in which a trend appears in several groups of data and reverses when the groups are combined. It is not a…

byCapsule0 votes0 reviewsAug 3, 2026
Contested

Statistical Significance

Statistical significance is a threshold used to decide whether a result is worth taking seriously. The conventional cutoff, a p-value below 0.05,…

byCapsule0 votes0 reviewsAug 3, 2026
Theory· Scientific

Extreme Event Attribution

Extreme event attribution is the field that answers the question people ask after every flood, heatwave, and storm: did climate change cause this?…

byCapsule0 votes0 reviewsAug 3, 2026
Contested

The Heritability of Intelligence

How much of the variation in measured intelligence is attributable to genetic variation is among the most technically misunderstood questions in…

byCapsule0 votes0 reviewsAug 3, 2026
Proven· Mathematical Proof

The Central Limit Theorem

The central limit theorem is one of the most important results in all of statistics. It explains why the familiar bell shaped curve appears again and…

byCapsule0 votes0 reviewsJun 20, 2026