Science & Trust → Reliability & Validity

Proven reliability.
Rigorous validity.

The IRIS Behavioral Assessment is a scientifically validated, non-cognitive measurement tool built on decades of behavioral research. With more than 9,000 participants in its normative sample and cited in over 1,000 academic studies, IRIS delivers data-driven results with exceptional reliability, validity, and EEOC compliance.

.65
Test-Retest (Males)
Correlation coefficient over 6–12 months
.71
Test-Retest (Females)
Correlation coefficient over 6–12 months
.95–.99
Inter-Rater Agreement
Agreement between expert evaluators
.53–.95
Cronbach's Alpha
Internal consistency across all scales
The Foundation

Built on Dr. Harrison Gough's Adjective Check List

The IRIS Behavioral Assessment is grounded in the Adjective Check List (ACL), a landmark psychological instrument created by Dr. Harrison G. Gough and Alfred B. Heilbrun, Jr. at the University of California, Berkeley. First developed in the early days of the Institute of Personality Assessment and Research, the ACL has been in continuous use since 1952 and is one of the 100 most frequently used and cited tests in psychology.

Dr. Gough (1921–2014) was Professor Emeritus at UC Berkeley and one of the most influential figures in psychological assessment. His two defining works — the California Psychological Inventory (CPI) and the Adjective Check List (ACL) — have each been translated into more than 40 languages and are backed by thousands of academic citations across decades of international research.

IRIS modernizes the ACL with a dynamic, self-descriptive model of 300 adjectives that generates highly personalized behavioral insights. By adding a Real vs. Ideal measurement layer, IRIS transforms a robust assessment instrument into a development-oriented growth tool — revealing not just where someone is, but where they want to go.

  • ACL cited in over 1,000 published academic studies
  • Developed at UC Berkeley Institute of Personality Assessment
  • Translated into more than 40 languages for cross-cultural research
  • Used by researchers in architecture, law, medicine, management, and more
  • Six work success factors realigned in 2012 to reflect workplace relevance
The 37 ACL Scales — Six Work Success Factors
Managing Self
Self-control, personal adjustment, ideal self, self-confidence
Thinking & Deciding
Intraception, creative personality, origence-intellectence
Getting Things Done
Achievement, endurance, order, change, autonomy
Managing Work
Dominance, counseling readiness, military leadership
Working With People
Affiliation, nurturance, exhibition, deference, succorance
Leading People
Influence, vision, interpersonal effectiveness
The ACL's 37 scales measure behavioral attributes across five domains: modus operandi, need, topical, transactional analysis, and origence-intellectence — providing a multi-dimensional view that goes beyond simple personality categorization.
Reliability

Consistency you can trust.

Three forms of reliability evidence ensure that IRIS measures are stable, consistent, and free from measurement error.

Test-Retest Reliability

IRIS demonstrates strong stability of results over time, with correlation coefficients averaging .65 for males and .71 for females across a six-month to one-year interval. Built-in authenticity algorithms detect random, extreme, or inconsistent responses to ensure accuracy and data integrity.

Inter-Rater Reliability

Studies show near-perfect agreement between expert evaluators (r = .95 to .99), confirming that IRIS results align with professional psychological assessments — independent of who is interpreting the data.

Internal Consistency

Using Cronbach's Alpha, IRIS scales demonstrate high internal reliability ranging from .53 to .95, showing that each behavioral trait is measured cohesively across multiple data points within the instrument.

Validity

Measuring what matters.

Validity evidence demonstrates that IRIS measures the right things, accurately, across diverse populations and contexts.

Content Validity

Normalized with a diverse group of more than 9,000 participants across ages, genders, and professions. Translated into 25 languages, ensuring broad cross-cultural applicability.

Construct Validity

Advanced factor analysis organizes 300 adjectives into 37 behavioral scales and six global factors, capturing the full spectrum of human behavior with strong convergent and discriminant validity.

Criterion Validity

IRIS scales correlate significantly with established instruments — the California Psychological Inventory (CPI) and the Minnesota Multiphasic Personality Inventory (MMPI) — confirming predictive alignment with validated psychological measures.

Cross-Cultural Validity

Rooted in the Adjective Check List, one of the most widely translated psychological instruments in history, the ACL has been successfully used in cross-cultural research across dozens of languages and countries.

EEOC Compliance

Fair, equitable, and legally compliant.

Independent studies confirm that IRIS results are non-discriminatory across race, gender, age, and disability status. The assessment fully complies with Title VII, ADA, and ADEA standards, ensuring fairness in all selection, development, and coaching applications.

  • Title VII of the Civil Rights Act
  • Americans with Disabilities Act (ADA)
  • Age Discrimination in Employment Act (ADEA)
  • Non-discriminatory across race, gender, age, disability
Normative Sample
9,000+
Participants
25
Languages
37
Behavioral Scales
1,000+
Academic Studies

Normalized across diverse ages, genders, and professions — ensuring the assessment is meaningful and fair for a global workforce.

How IRIS Compares

Built for growth, not just description.

Many behavioral assessments are excellent tools — each designed with a specific purpose. The difference with IRIS is orientation: most tools describe where people are; IRIS is built to develop where people can go.

DimensionIRISOther assessments (Hogan, DISC, MBTI, Predictive Index, etc.)
What it measuresCoachable, changeable behaviors and mindsets — what people can growFixed personality traits, stable preferences, or inborn type
Change lensBuilt for growth — measures current awareness and desired directionMostly descriptive; rarely developmental
Time orientationDynamic: captures how someone evolves over timeStatic: a one-time snapshot
What the data showsWhere someone is now, where they want to grow, and the size of the stretchEnduring dispositions, stable styles, or dominant talents
Coaching conversation"Here's how you show up. What do you want to dial up next?""Here's who you are" or "Here's your type"
Underlying modelModernized ACL — measures ~100 attributes, Real vs. Ideal to reveal growth gapsTrait psychology, Jungian typology, behavioral styles, or factor models

A note on comparison: Tools like Hogan, DISC, MBTI, CliftonStrengths, and the Predictive Index are widely used and well-validated within their intended purposes. IRIS is not a replacement for these instruments in the contexts they are designed for. The distinction is orientation: static tools answer "who are you?" with precision. IRIS is designed to answer "how are you growing?" — making it uniquely suited to coaching, development, and longitudinal tracking across the employee lifecycle.

Applications

Validated for use across the full employment lifecycle.

Education & Workforce Readiness

Track and enhance non-cognitive skills that improve academic outcomes and workforce readiness.

Hiring & Development

Match candidates to roles, identify leadership potential, and guide coaching plans with precision.

Organizational Growth

Use IRIS data to develop cultures of self-awareness, engagement, and performance improvement.

Get in Touch

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Download the technical documentation.

Review the full reliability and validity evidence and the comparative assessment landscape in our technical documents.