Methodology & Scientific References
Understanding the science behind our IQ assessment
Important Disclaimer
This online IQ test is designed for educational and entertainment purposes only. It is NOT a clinical diagnostic tool and should NOT be used for medical, psychological, or official assessment purposes.
If you require a formal cognitive assessment, please consult a licensed psychologist or healthcare professional who can administer standardized, validated tests in a controlled environment.
What is Intelligence Quotient (IQ)?
Intelligence Quotient, or IQ, is a score derived from standardized tests designed to assess human intelligence. The concept was first introduced by German psychologist William Stern in 1912 as a method to score early intelligence tests.
Modern IQ tests produce scores for different cognitive domains that are combined into a single score. The tests are designed so that the average score is 100, with a standard deviation of 15 points. This means that approximately 68% of the population scores between 85 and 115.
Item Response Theory (IRT)
Our test is based on Item Response Theory (IRT), a modern psychometric paradigm for the design, analysis, and scoring of tests. Unlike classical test theory, IRT focuses on the relationship between an individual's response to a test item and their underlying ability level.
Three-Parameter Logistic Model (3PL)
We use the 3PL model, which considers three parameters for each question:
- aDiscrimination (a) - How well the item differentiates between test-takers of different ability levels
- bDifficulty (b) - The ability level at which 50% of test-takers would answer correctly
- cGuessing (c) - The probability that a low-ability test-taker would answer correctly by guessing
Computerized Adaptive Testing (CAT)
Our platform implements Computerized Adaptive Testing (CAT), a form of computer-based test that adapts to the examinee's ability level. CAT successively selects questions for the purpose of maximizing the precision of the exam.
After each response, the system recalculates the ability estimate and selects the next question that will provide the most information about the test-taker's true ability level.
Advantages of CAT
- • Shorter test duration while maintaining accuracy
- • Personalized testing experience
- • Reduced test anxiety from appropriate difficulty
- • More precise ability estimation
WAIS-IV Structure
Our test is inspired by the structure of the Wechsler Adult Intelligence Scale (WAIS-IV), the worldwide gold standard for adult intelligence assessment. The WAIS-IV measures intelligence through five main cognitive indices.
Each cognitive index contributes equally to the overall score, ensuring a comprehensive assessment of diverse mental abilities:
Verbal Comprehension (VCI)
Assesses verbal reasoning, concept formation, and acquired knowledge through analogies and vocabulary.
Visual Spatial (VSI)
Measures the ability to analyze and construct geometric designs, mental rotation, and spatial visualization.
Fluid Reasoning (FRI)
Evaluates logical reasoning with novel stimuli, including Raven's progressive matrices and pattern recognition.
Working Memory (WMI)
Measures the ability to maintain and manipulate information in short-term memory.
Processing Speed (PSI)
Assesses visual scanning speed, discrimination, and information processing.
Note: This online test is inspired by the WAIS-IV structure but is not a substitute for professional assessment.
Scientific References
Lord, F. M. (1980)
Applications of Item Response Theory to Practical Testing Problems.
Hillsdale, NJ: Lawrence Erlbaum Associates.
Wainer, H. et al. (2000)
Computerized Adaptive Testing: A Primer (2nd ed.)
Hillsdale, NJ: Lawrence Erlbaum Associates.
Embretson, S. E., & Reise, S. P. (2000)
Item Response Theory for Psychologists.
Mahwah, NJ: Lawrence Erlbaum Associates.
Raven, J. C. (1936)
Mental Tests Used in Genetic Studies: The Performances of Related Individuals in Tests Mainly Educative and Mainly Reproductive.
MSc Thesis, University of London.
Cattell, R. B. (1963)
Theory of Fluid and Crystallized Intelligence: A Critical Experiment.
Journal of Educational Psychology, 54(1), 1-22.
Test Limitations & Considerations
While our test is based on established psychometric principles, it's important to understand its limitations:
- • Online tests cannot control for environmental factors (distractions, fatigue, etc.)
- • Results may vary based on device, internet connection, and testing conditions
- • The test measures specific cognitive abilities, not overall intelligence or potential
- • Cultural and educational background may influence performance
- • A single test cannot capture the full complexity of human intelligence
Intelligence is multifaceted and includes emotional, creative, practical, and social dimensions that cannot be measured by matrix reasoning tests alone.
Your Privacy & Data
We take your privacy seriously. Here's how we handle your data:
- • No personal information is required to take the test
- • Test results are processed anonymously
- • We do not sell or share your data with third parties
- • Email collection is optional and only used if you choose to receive your results
100% Free • No Registration Required