Methodology & limits

This page explains how the dataset statistics are computed and what to keep in mind when interpreting the results.

Overview

Universal IQ Test statistics summarize performance in a large online dataset. The numbers are descriptive: they show who took the test and how they scored on this format. They are not clinical IQ diagnoses and they do not represent population averages.

Data sources

Aggregates are computed from completed IQ tests in the Universal IQ Test database. Seed data used for development or demos is excluded from all published statistics. Country charts exclude blank country codes. Data fields include test score, time taken, and self-reported demographics.

Demographics and coverage

• Age is captured in bands (Youth, Young Adult, Adult, Senior) and is used for age-normalization.
• Gender is currently recorded as male or female, so gender statistics cover those two categories only.
• Education level and study area are self-reported and standardized into a fixed set of categories.
• Country is self-reported and mapped to ISO codes when provided.

Scoring and IQ scale

The underlying test score is based on number of correct answers, with time taken used as a tie-breaker. For published statistics, we convert scores to percentiles and then map those percentiles onto a standard IQ-style scale (mean 100, standard deviation 15). This makes charts easy to interpret but does not turn the online test into a clinical assessment.

Validation

Validated results pass internal checks for timing, completion, and consistency. The "all results" view includes both validated and unvalidated submissions, which can be noisier in small segments.

Statistics we publish

• Means, medians, and percentile ranges (p10/p25/p50/p75/p90) for each category.
• 95% confidence intervals for means, based on sample size and score dispersion.
• Sample sizes (N), validated counts, and validation rates.
• Average time taken for additional context.

Dispersion is approximated from the interquartile range (p25-p75) when full variance is not stored. Confidence intervals are approximate and should be interpreted as margins of error for the mean.

Adjustments and comparisons

Some pages provide age-adjusted means. These re-weight group averages to a common age distribution to reduce confounding from age mix differences. Other charts (such as distributions) remain unadjusted and reflect the raw dataset.

Limits and interpretation

• Self-reported demographics may contain errors or omissions.
• Sample sizes vary by segment, so small groups are more volatile.
• The dataset reflects visitors to Universal IQ Test and is not a representative population sample.
• Online testing conditions (device, language, distraction) can shift performance.
• Differences between groups are usually small and distributions overlap heavily.

FAQ