PRECEDENT ASSESSMENT GROUP

What Research Says About Written Police Promotional Examinations and Assessment Centers

Published: August 3, 2026  |  Last Reviewed: August 3, 2026  |  Reviewed by Precedent Assessment Group

Introduction

Police promotional processes may include written job knowledge examinations, structured interviews, work simulations, assessment center exercises, training and experience evaluations, and other job-related selection procedures.

The appropriate combination depends on the target rank, the underlying job analysis, agency requirements, civil service rules, collective bargaining provisions, budget, candidate population, available professional expertise, and the intended use of the results. No single method is universally superior — the right approach depends on what an agency actually needs to measure and the resources available to measure it well.

What Written Job Knowledge Examinations Measure

Properly developed job knowledge tests can assess the knowledge required for successful job performance. The U.S. Office of Personnel Management describes job knowledge tests as assessments of technical or professional expertise in specific knowledge areas — evaluating what a candidate currently knows, constructed on the basis of an analysis of the tasks the job requires.

Building a defensible job knowledge test depends on several things working together:

  • Clearly defining the knowledge being measured
  • Connecting tested knowledge to important job responsibilities
  • Using agency-approved source materials
  • Confirming source editions and effective dates
  • Developing an examination blueprint before writing items
  • Linking every scored item to an approved source and citation
  • Reviewing items for accuracy and rank relevance
  • Fairly sampling relevant content across the domain being tested
  • Documenting agency subject matter expert participation

OPM guidance also notes that job knowledge tests are generally viewed favorably by applicants, in part because they have high face validity — candidates can see the direct connection between what's tested and what the job requires. This does not, on its own, establish legal or psychometric validity for any specific exam; it describes candidate perception, not a substitute for proper development and documentation.

What an Assessment Center Is

An assessment center is not a single test or a specific location — it's a method. The International Taskforce on Assessment Center Guidelines and OPM both describe an assessment center as involving multiple assessment components, behavioral simulation exercises, multiple trained assessors, standardized behavioral observation, systematic recording of behavior, behavior-based ratings, and an established method for integrating those ratings into a final score.

A multiple-choice written examination may be one component of a broader promotional process, but a written exam alone is not an assessment center. The International Taskforce on Assessment Center Guidelines is explicit on this point: a procedure should not be represented as an assessment center unless it includes at least one, and usually several, job-related simulation exercises requiring the candidate to demonstrate a constructed response — not simply select an answer from a list. The term describes a specific, multi-method, multi-assessor process — not a general label for any promotional testing activity.

Why Agencies Sometimes Combine Methods

A written examination can measure job knowledge — what a candidate knows. Structured interviews, simulations, and assessment center exercises can provide different information: how a candidate applies communication, judgment, planning, leadership, supervisory decision-making, administrative reasoning, and prioritization under realistic conditions.

OPM's guidance on designing an assessment strategy confirms that different assessment methods measure different things and can be combined to build a more complete picture of a candidate — a concept known as incremental validity, where combining methods can improve on what any single method captures alone. Importantly, this improvement is not simply additive; how much value combining methods adds depends on the specific combination and what the agency actually needs to measure.

Combining methods does not, by itself, make a process validated, fair, legally defensible, or free from adverse impact. Those outcomes depend on how each method was developed, administered, and scored — not on the number of methods used.

The two studies below specifically examine assessment centers — a multi-method, simulation-based process — not standalone written job knowledge examinations of the kind described earlier in this article. They are included to illustrate how rigorous evaluation of a promotional process can look, not as evidence that any particular written examination has itself been separately validated.

What Assessment Center Research Shows

A study abstracted by the U.S. Office of Justice Programs examined the predictive validity of the assessment center approach in selecting police managers, correlating assessment center ratings against later job performance ratings from supervisors. The study reported a validity coefficient of 0.47 — a meaningful, favorable relationship between assessment center performance and later on-the-job management success, in the specific agencies and process studied. The study also found that the centers examined relied heavily on evidence of interpersonal sensitivity and communication skill in reaching their ratings, and that officers' promotional outcomes often aligned with supervisors' independent judgment of who deserved advancement.

One study of this kind does not guarantee that every assessment center will predict managerial performance equally well elsewhere. Outcomes depend on the specific job, candidate population, exercises used, assessor training, scoring procedures, administration quality, and how results are ultimately used. This finding describes an assessment center specifically, not a standalone written job knowledge examination.

Assessment Center Economic Utility Research

A separate study by Thornton and Potemra (2010), published in Public Personnel Management, examined whether the cost of running an assessment center as part of a police sergeant promotional process was justified by its measurable benefits. In the program studied, assessing 208 candidates cost a total of $158,970 — about $764 per candidate. Based on 22 initial sergeant promotions from that process, the study's researchers estimated the total utility (measurable value) at at least $414,943, or roughly $1,995 per candidate assessed and at least $18,861 per candidate actually selected. The study noted that utility estimates would be substantially higher under alternative assumptions about costs, validity, and the number of promotions made from the resulting list over time.

These figures describe one specific assessment center program, with its own costs, candidate pool, and assumptions. They are not a guaranteed financial return for any other agency's process, and they do not describe the cost or value of a standalone written job knowledge examination — the actual value of any promotional process depends on that agency's own costs, candidate population, and how effectively the process identifies strong performers.

Limitations and Continuing Professional Debate

Professional literature on assessment centers includes both supporting evidence and ongoing debate about precisely what assessment center scores measure — whether they capture stable, generalizable leadership competencies or largely reflect performance in that specific set of exercises on that specific day. Assessment centers can provide useful, structured information about how a candidate performs under realistic conditions, but agencies should not treat every assessment center score as conclusive proof of a fixed leadership trait. This is a genuine, ongoing area of professional discussion, not a settled question — and it does not undermine the value of a properly developed process, but it does mean results should be interpreted with appropriate caution.

Legal and Agency Responsibilities

The EEOC's fact sheet on employment tests and selection procedures confirms that tests and other selection tools "can be an effective means of making employment decisions" — but the same guidance warns that a test or selection procedure creates legal exposure whenever it disproportionately excludes a protected group and cannot be justified as job-related and consistent with business necessity. Under the related Uniform Guidelines on Employee Selection Procedures, the employer — not the testing vendor — remains legally responsible for how a selection procedure is used. A vendor's marketing claims do not, by themselves, establish that a test is valid or legally defensible.

Agencies planning a promotional process should generally expect to:

  • Maintain records supporting the selection and scoring process
  • Evaluate the process for potential adverse impact
  • Ensure the intended use of scores corresponds to the evidence actually supporting that use
  • Consider appropriate alternatives where legally required
  • Involve professional, legal, civil service, and labor review as appropriate to the agency's obligations

This article provides general educational information. It is not legal, employment, or psychometric advice, and it does not interpret federal or state law for any specific agency's circumstances.

Questions to Ask a Police Promotional Testing Vendor

A practical checklist for chiefs, HR directors, and purchasing officials evaluating any vendor — not just this one:

  • What job analysis supports the process?
  • How will the approved source list be established?
  • How will source editions and effective dates be documented?
  • How is the examination blueprint developed and approved?
  • How is each scored item connected to job-related knowledge and an approved source?
  • Who writes, reviews, and approves the items?
  • What qualifications do writers, reviewers, assessors, and consultants hold?
  • How are answer keys separated and protected?
  • How are examination materials transferred, inventoried, returned, retained, and destroyed?
  • What administration instructions are included?
  • How will candidate identities and results be protected?
  • How will examinations be scored?
  • What reports will the agency receive?
  • Will item statistics or candidate-level reports be included?
  • What candidate challenge procedures are included?
  • What professional review, validation, or adverse-impact analysis is actually included — specifically?
  • What responsibilities remain with the agency?
  • How are conflicts involving candidate coaching addressed?

Precedent Assessment Group's Approach

Written job knowledge examinations, assessment centers, and other promotional methods are related but distinct, each with its own body of research. The studies above provide useful context on rigorous promotional-process evaluation — they are not evidence that any specific written examination, including ours, has itself been validated.

The written proposal and client agreement for each engagement identify the specific scope, including: approved source materials, examination blueprint, item development requirements, source citation requirements, agency subject matter expert participation, professional review procedures, administration responsibilities, scoring responsibilities, security procedures, chain-of-custody procedures, reporting deliverables, challenge support, authorized technology, and qualified professional participation where included. Our engagement process and Security, Ethics & Chain of Custody practices are described in full elsewhere on this site, along with the background of our founder.

We currently develop examinations for Sergeant, Lieutenant, and Detective promotional processes, using the same source-cited methodology described throughout this article.

No examination or service is described as validated, psychometrically sound, bias-free, legally defensible, attorney-approved, guaranteed, or compliant with every applicable law unless sufficient work supporting that specific statement has actually been completed and documented for that particular engagement.

Next Steps

Agencies planning a promotional process can:

Sources and Further Reading