Introducing AGCT-1o

OpenIQ today launches AGCT-1o, a contemporary digital implementation of one of history's most significant cognitive assessments: the U.S. Army General Classification Test (AGCT). Originally deployed during World War II, the AGCT was instrumental in assessing the general learning ability of millions. Our AGCT-1o brings this historical assessment into the 21st century, leveraging advanced psychometric techniques like Item Response Theory (IRT) to provide a reliable and accessible measure of cognitive abilities.

This initial release, version 1o, serves as a research preview available on the OpenIQ platform. It allows users to experience the unique item styles of the AGCT while benefiting from modern, precise scoring. We invite you to explore AGCT-1o, contribute to its ongoing validation, and gain insights into your verbal, quantitative, and spatial reasoning skills.

The AGCT Legacy and its Successors

The original Army General Classification Test (Forms 1a, 1b, 1c, 1d) was a critical tool for the U.S. Army from 1940 through the mid-1940s. Its purpose was clear: classify millions of inductees based on their "ability to learn quickly the duties of a soldier." It focused on core cognitive functions:

• Verbal Comprehension (Vocabulary items)
• Quantitative Reasoning (Arithmetic word problems)
• Spatial Thinking (Block counting items)

Presented in a timed (40 minutes), multiple-choice format, these items were arranged spirally to measure general ability while minimizing specific educational or cultural loading. The AGCT achieved remarkably high reliability (coefficients consistently above 0.92, often cited as ≥ 0.95) and demonstrated significant predictive validity for success in numerous Army training programs, correlating around 0.40 with Officer Candidate School grades despite range restriction. It also correlated strongly (0.73) with educational attainment, acting as an effective screening tool.

The AGCT laid the groundwork for subsequent military testing. While not a direct replacement, the modern Armed Services Vocational Aptitude Battery (ASVAB) evolved from the principles established by the AGCT and later batteries. However, the ASVAB has a broader scope, measuring specific vocational aptitudes (mechanical, electronic, etc.) alongside general cognitive ability (via the AFQT score) for both enlistment qualification and detailed job classification. AGCT-1o, in contrast, focuses specifically on replicating the historical measure of general learning ability derived from the original AGCT's content domains.

AGCT-1o: Modern Psychometric Enhancement

While preserving the item content and structure, AGCT-1o introduces key enhancements:

• Digital Platform: Accessible online, allowing for convenient testing and automated administration and scoring.
• Item Response Theory (IRT) Scoring: Instead of simple raw score counts, AGCT-1o applies IRT models. This estimates the test-taker's underlying ability level more accurately by considering the difficulty and discrimination of each specific item answered correctly or incorrectly. This provides a more robust foundation for score interpretation than the original raw-to-standard score conversion (which used M=100, SD=20).
• Bias Analysis (Ongoing): While adapting historical items, we are actively analyzing item performance across demographic groups using techniques like Differential Item Functioning (DIF) analysis. Our goal is to ensure fairness and minimize potential bias, aiming for DIF measures below established thresholds (e.g., <0.05 effect size) where data permits.
• Future Adaptivity: The IRT calibration makes future Computerized Adaptive Testing (CAT) versions feasible, potentially shortening test times while maintaining high precision.

AGCT-1o combines historical items with modern IRT scoring

Psychometric Profile (Based on Historical Data & Preview Analysis)

The AGCT was renowned for its strong psychometric properties, which AGCT-1o aims to reflect and build upon:

• Exceptional g-Loading: Historical studies and our preliminary analyses confirm the AGCT structure's high correlation with the general intelligence factor ('g'), estimated at >0.925. This underscores its strength as a measure of general learning ability, comparing favorably to established benchmarks like the WAIS-IV (g ≈ 0.90) or Raven's Progressive Matrices (g ≈ 0.85).
• High Reliability: The original AGCT consistently demonstrated reliability coefficients above 0.92, often reaching 0.95-0.97. Our digital version maintains high internal consistency (preliminary α ≈ 0.91). Test-retest reliability was also robust historically (r = 0.82) with minimal practice effects.
• Strong Predictive Validity: The AGCT historically showed significant correlations with success in academic and vocational training (e.g., r ≈ 0.40 for OCS grades, r ≈ 0.35 for mechanics training), even with restricted samples. It also correlated highly with established IQ tests (e.g., r = 0.90 with Army Alpha, r = 0.83 with Otis Higher).

Interpretation and Use

AGCT-1o yields a standard IQ score (scaled to M=100, SD=15 for modern comparison, derived from IRT) and percentile ranks based on our developing norms. The score reflects:

• An estimate of overall general learning ability ('g').
• Performance across verbal, quantitative, and spatial reasoning tasks.

As a research preview, scores should be interpreted with caution. They provide a valuable estimate but are not intended for clinical diagnosis or high-stakes decisions at this stage. It serves as an excellent tool for self-exploration and understanding cognitive patterns.

Accessing AGCT-1o and Research Goals

AGCT-1o is now available for exploration on the OpenIQ platform. By participating in this research preview, you help us:

• Collect contemporary performance data on historical items.
• Refine IRT parameters and scoring algorithms.
• Build robust, representative norms for the 21st century.
• Conduct thorough fairness and bias analyses (DIF).
• Assess the feasibility and design of future adaptive versions.

We encourage users to share feedback on the testing experience, item clarity, and score interpretation via our contact form.

Conclusion

AGCT-1o represents OpenIQ's commitment to making significant historical assessments accessible through modern technology. By digitizing and enhancing the Army General Classification Test, we offer a unique tool for measuring general cognitive ability with strong psychometric foundations. Experience AGCT-1o today and contribute to the advancement of open cognitive assessment.