Apps

🧪 This platform is in early beta. Features may change and you might encounter bugs. We appreciate your patience!

Lord's Paradox

Also Known As: Lord's Statistical Paradox
Discourse Mechanics ID: lords_paradox

Definition

A statistical paradox where two legitimate analytical methods applied to the same data yield opposite conclusions. Typically arises when comparing groups on change scores versus using analysis of covariance (ANCOVA) to adjust for baseline differences. The choice of method encodes different causal assumptions.

Examples

Comparing weight change between men and women: raw change scores show no difference, but ANCOVA adjusting for initial weight shows women gained more. Both analyses are mathematically correct but make different assumptions.

A school district tests two teaching methods by measuring reading scores at the start and end of the year. A simple analysis of score gains shows no difference between methods. But when analysts adjust for students' starting scores using ANCOVA, Method B appears significantly better — both analyses use the same data and are statistically valid.

A clinical trial compares two diets for weight loss. Analyzing the raw pounds lost per group shows Diet A wins. But when researchers control for participants' baseline weight, Diet B appears superior because heavier participants — who lose more in absolute terms — were unevenly distributed across groups. Both conclusions are mathematically defensible.

Verification Steps
Verification Steps
Binary yes/no questions that an AI must answer to detect a reasoning pattern in a text.
Each of the 452 aspects has verification steps — simple yes/no questions designed to systematically detect whether a pattern appears in a text. For ad hominem: "Does the argument attack a person rather than their claim?" For false dichotomy: "Are only two options presented when more exist?" This ensures consistent, reproducible analysis.

Binary (yes/no) questions an LLM must answer to identify this aspect:

  1. 1

    Are pre-post measurements being compared across two groups?

    Type: binary
  2. 2

    Do different valid statistical methods (e.g., change scores vs. ANCOVA) yield contradictory conclusions?

    Type: binary
  3. 3

    Is the contradiction driven by different assumptions about what constitutes a 'fair comparison'?

    Type: binary
Deep Dive
The expandable detail section on each aspect page with examples, psychology, and counter-strategies.
The Deep Dive section provides in-depth information about each aspect: a real-world example showing the pattern in action, an explanation of why it works psychologically, practical advice on how to counter it, alternative names, and links to related aspects.

Hierarchical Context