The Acumen Capacity Index®

The Acumen Capacity Index (ACI) measures how clearly a person thinks, judges and makes decisions. It is built on axiology, the study of value and judgment, and it scores six core dimensions of thought across two perspectives: how a person sees the world around them, and how they see themselves. Alongside those scores, ACI surfaces the blind spots that emotional bias creates in each perspective.

What the Acumen Capacity Index Measures

ACI measures clarity of thought: how accurately a person perceives people, tasks and systems, and how much emotional bias distorts that perception. Every person filters experience through a pattern of thought that determines which details they notice first and which they overlook entirely. ACI puts a score on that pattern instead of leaving it to a hiring manager's intuition.

The assessment evaluates three distinct dimensions of thought:

• Intrinsic (feeling) — perception of people, relationships and individual worth.
• Extrinsic (doing) — perception of tasks, practicality, comparison and usefulness.
• Systemic (thinking) — perception of structure, order, definitions and rules.

Everyone uses all three in varying degrees, and all three are engaged in any decision. The differences in clarity between them are what produce a person's natural talents and their characteristic blind spots.

The Six Core Dimensions ACI Scores

Each of the three dimensions of thought is scored twice: once for how a person judges the external world, and once for how they judge themselves. That produces the six core dimensions reported in the ACI. Most descriptions of ACI stop at the three dimensions, which is why the world view and self view scores are worth setting out in full.

A leader can score high on Systems Judgment and low on Understanding Others, which typically shows up as elegant strategy that people quietly refuse to execute. The gap between world view and self view scores is often the more useful finding: someone who reads other people accurately but cannot see their own contribution clearly will consistently undersell themselves in a promotion conversation.

The Science Behind ACI: Axiology and the Hartman Value Profile

ACI is built on axiology, the formal study of value and judgment developed by philosopher Robert S. Hartman. Hartman's contribution was to treat judgment as something that could be measured rather than described, and he formalized it in the Hartman Value Profile (HVP), a ranking-based instrument that uses mathematical structure to analyze how a person orders what matters.

TTI Success Insights released its first version of an axiology-based assessment in the early 2000s and released the TTI Success Insights Acumen Capacity Index in 2010, built on the Hartman Value Profile (HVP) and the HVP Manual of Interpretation. TTI's research team continues to publish its psychometric work at ttiresearch.com.

For a plain-language explanation of the underlying science, see what axiology means in assessments, and for the history and report structure, see ACI: what you need to know.

Where Organizations Use ACI

Organizations use ACI across hiring, coaching, leadership development and role alignment to better understand whether a person's thinking patterns match the demands of a role.

Hiring for judgment-heavy roles

ACI helps organizations evaluate how candidates think, process information, exercise judgment, and make decisions, especially in roles where the quality of those decisions has a significant impact. By comparing an individual's ACI results with the thinking and judgment demands of a role, hiring teams can gain deeper insight into potential fit, identify possible blind spots, and make more informed selection decisions. TTI's hiring and selection approach pairs ACI with job benchmarking rather than using the assessment in isolation.

Leadership Development

ACI helps leaders understand how they think, process information, and make decisions—and where their thinking may become imbalanced under pressure. By examining the different dimensions of thinking and judgment together, leaders gain greater clarity into how they approach situations, evaluate information, and determine a course of action. This broader perspective helps leaders recognize blind spots, understand biased perspectives, and make more thoughtful, well-rounded decisions.

Executive coaching

ACI gives coaches a structured, objective way to explore how clients think, interpret situations, and make decisions. Rather than relying solely on observation or subjective feedback, coaches can use ACI results to uncover potential blind spots, challenge assumptions, and create more meaningful conversations around self-awareness and development. The assessment provides a shared language for turning insights about thinking and judgment into practical coaching and behavioral change.

Using ACI Responsibly in Hiring Decisions

ACI should be one input in a documented selection process, never a standalone pass or fail cutoff. That is the position TTI takes, and it is the position U.S. employment law effectively requires of any assessment used to make employment decisions.

TTI designs its assessments in accordance with federal employment law and EEOC guidance, validates them using content, criterion-related and construct validity methods, and applies the Uniform Guidelines on Employee Selection Procedures and the disparate treatment and disparate impact principles that follow from them. The full statement is published on TTI's compliance page.

Practically, this means three things for an employer. Benchmark the job before you assess anyone, so the standard comes from the role rather than from a preferred candidate. Use ACI alongside structured interviews and other evidence rather than as a gate. And keep records of how scores were used, because that record is what an adverse impact analysis will eventually examine.

How ACI Compares to TTI's Other Sciences

ACI answers a question none of TTI's other single sciences answers: how clearly does this person see the situation in the first place. The five sciences are designed to be read together, and each one addresses a different question about the same person.

ACI can be run on its own, but it is most often delivered inside a multi-science assessment such as TriMetrix HD, where acumen scores are read against behaviors, motivators, and competencies in the same report.

Frequently Asked Questions

Is the Acumen Capacity Index scientifically valid?

ACI is built on Robert S. Hartman's formal axiology and validated by TTI's in-house research team using content, criterion-related and construct validity methods, as set out on TTI's compliance page. TTI publishes its psychometric research at ttiresearch.com, and buyers evaluating ACI for selection use should request the current technical documentation directly rather than relying on a marketing summary. That is the standard any assessment vendor should be held to.

Can ACI legally be used to make hiring decisions?

Yes, when it is used as one input in a documented, job-related selection process rather than as a standalone cutoff. U.S. employers using any assessment for selection are subject to the Uniform Guidelines on Employee Selection Procedures and to EEOC guidance on disparate treatment and disparate impact. TTI designs its assessments in accordance with those requirements, but legal defensibility depends on how the employer uses the results, including whether the role was benchmarked and whether adverse impact is monitored.

How is ACI different from a personality test?

A personality test describes what a person tends to do; ACI describes how clearly they see what they are doing. DISC, for example, will tell you that someone is direct and fast-paced. ACI will tell you whether that person accurately perceives the people they are being direct with. The two are complementary, which is why they are frequently delivered together.

What is the difference between ACI and the Hartman Value Profile?

The Hartman Value Profile is Robert S. Hartman's original instrument for measuring value judgment. ACI is built on the HVP Manual of Interpretation and extends it into a workplace assessment that reports six scored dimensions across world view and self view, with narrative interpretation written for hiring, coaching and development rather than for philosophical research.

Does ACI work outside the United States?

Yes. TTI assessments are used in more than 100 countries and delivered through a partner network of over 7,000 experts, with reports available in multiple languages. Availability of specific ACI report formats varies by region, so confirm the current language list with your TTI representative before rolling ACI out across markets.