Employer guideRead at source, 9 September 2026
Pre-Employment Assessments: the Two Rules That Decide Whether You Can Use One
A pre-employment assessment is a selection procedure, and federal law treats it as one. Under the Uniform Guidelines on Employee Selection Procedures, any selection procedure with an adverse impact is considered discriminatory unless it has been validated — and adverse impact is generally presumed where one group's selection rate is less than four-fifths of the highest group's. Separately, the ADA forbids a medical examination before a conditional job offer, which is where personality inventories get employers into trouble. Two questions decide whether you can use a test: can you produce a validation study for roles like yours, and is the test a medical examination in disguise.
The guidelines do not care what you call it
A cognitive test, a situational judgement questionnaire, a typing test, a structured scoring rubric, a physical ability trial — all of them are selection procedures. Section 1607.3(A) is the sentence the whole subject hangs on:
"The use of any selection procedure which has an adverse impact on the hiring, promotion, or other employment or membership opportunities of members of any race, sex, or ethnic group will be considered to be discriminatory and inconsistent with these guidelines, unless the procedure has been validated in accordance with these guidelines, or the provisions of section 6 below are satisfied."
Read the structure of it. Adverse impact does not make a test unlawful by itself; it shifts the burden. Once the impact is there, the question becomes whether you can produce the validation, and "the vendor says it's validated" is not the same as having a study that covers a job like yours in a workforce like yours.
The four-fifths rule, and how to run it on your own data
Section 1607.4(D) sets the threshold that federal enforcement agencies apply:
"A selection rate for any race, sex, or ethnic group which is less than four-fifths (4/5) (or eighty percent) of the rate for the group with the highest rate will generally be regarded by the Federal enforcement agencies as evidence of adverse impact, while a greater than four-fifths rate will generally not be regarded by Federal enforcement agencies as evidence of adverse impact."
The arithmetic is straightforward and most employers have never done it. For each group, divide the number who passed by the number who took the test. Divide the lower rate by the highest rate. If the result is below 0.80, the guidelines treat that as evidence of adverse impact. It is a rule of thumb rather than a statistical test, and small samples make it jumpy — but it is the rule of thumb the agencies use, so it is the one to run first.
Four-fifths calculator
Three ways to validate, and only one of them is usually practical
Section 1607.5 recognises three approaches, and they are not equally available to a frontline employer.
- Criterion-related validity — a study showing the test scores predict job performance. Statistically demanding and sample-hungry; realistic for a large employer with a stable role and good performance data, and rarely realistic otherwise.
- Content validity — a demonstration that the procedure is a representative sample of the job's duties. This is the practical route for most frontline roles, and it is also the one that improves the test: a work sample that mirrors the actual task is easier to defend and better at predicting than a generic aptitude battery.
- Construct validity — a demonstration that the procedure measures a characteristic shown to be necessary for successful performance. The most conceptually demanding of the three and the least commonly relied on.
The practical translation for a warehouse, a care home or a fleet is unglamorous: a short work sample beats a personality inventory on every dimension that matters. It is easier to defend under content validity, easier to explain to a candidate, harder to coach for, and it does not raise the ADA problem below.
The line the ADA draws, and where tests cross it
Section 12112(d) separates the process into before and after a conditional offer. Before an offer, a covered entity shall not conduct a medical examination or make inquiries of a job applicant as to whether such applicant is an individual with a disability or as to the nature or severity of a disability. What you may do at that stage is inquire into the ability of an applicant to perform job-related functions.
After a conditional offer and before work begins, an employer may require a medical examination and condition the offer on the result — provided all entering employees in that job category are subjected to the same examination regardless of disability, the information is collected and maintained on separate forms and treated as a confidential medical record, and the results are used only as the ADA permits.
Where personality tests get employers into trouble
A physical ability test that measures whether someone can perform the job's actual tasks is generally not a medical examination. A questionnaire designed to reveal a mental impairment can be. That is the distinction to hold: the question is not whether the vendor calls it a personality assessment, it is whether the instrument is designed to identify a mental or physical impairment or health condition. If it is, it belongs after the conditional offer, applied to everyone entering that job category — not in the application flow.
Five questions for the vendor
- Show me the validation study — and specifically, does it cover a job like this one, in a workforce like ours? A study on office roles does not validate a test for a night-shift warehouse.
- Which validation strategy is it? Criterion, content or construct. The answer tells you how much of the argument you are inheriting and how much you would have to build.
- What adverse impact has the instrument shown, and in what populations? A vendor that has never measured it is telling you something.
- Has it been reviewed as a medical examination under the ADA? Ask for the reasoning, not the assurance.
- What is the accommodation process? For an applicant who needs an alternative format or extra time, there has to be one, and it has to be reachable before they abandon the application.
Where the answer to the first question is thin, the cheapest fix is usually not a different vendor. It is a shorter, job-specific work sample built and documented as content-valid — which is also the version a hiring manager will actually use. Our pre-screening questions guide covers the step before this one, and the assessment centre entry in our glossary covers the heavier end.
What a test costs you in applicants
Legal defensibility is one axis. Volume is the other, and it is the one that shows up in the vacancy.
Across the 891 Boostpoint-managed Meta campaigns in our 2026 Social Job Advertising Benchmark, the share of clickers who completed an application ran from 31% for caregiver roles down to 11% for registered nurse and 5% for therapy roles. The pattern is consistent: the more credentialed the candidate, the less patience they extend to your process. An assessment placed before any human contact is another completion event applied to people you have already paid for, and its cost lands hardest on exactly the roles you are struggling to fill.
That is not an argument against assessments. It is an argument about placement. A test that runs after a recruiter has decided a candidate is worth an hour is applied to a smaller number of people with a reason to finish it, and it costs a fraction as much per completed candidate as the same test placed in front of the funnel.
Frequently asked questions
Are pre-employment assessments legal?
Yes, subject to two constraints. Under 29 CFR 1607.3(A), the use of any selection procedure with an adverse impact on a race, sex or ethnic group is considered discriminatory unless the procedure has been validated in accordance with the Uniform Guidelines. And under 42 U.S.C. section 12112(d), an employer may not conduct a medical examination or ask whether an applicant is an individual with a disability before a conditional job offer, although it may inquire into the applicant's ability to perform job-related functions.
What is the four-fifths rule?
A selection rate for any race, sex or ethnic group that is less than four-fifths, or eighty percent, of the rate for the group with the highest rate will generally be regarded by federal enforcement agencies as evidence of adverse impact. A rate greater than four-fifths generally will not. It is calculated by dividing each group's pass rate by the highest group's pass rate, and it is a rule of thumb used by enforcement agencies rather than a statistical test.
How do you validate a pre-employment test?
The Uniform Guidelines recognise three approaches: criterion-related validity, showing that scores predict job performance; content validity, showing the procedure is a representative sample of the job's duties; and construct validity, showing the procedure measures a characteristic necessary for successful performance. For most frontline roles content validity is the practical route, which in effect means using a short work sample that mirrors the real task.
Can we give a personality test before making an offer?
It depends on whether the instrument is a medical examination. The ADA prohibits a medical examination before a conditional job offer, so a questionnaire designed to identify a mental impairment or health condition belongs after the offer, applied to all entering employees in that job category, with results kept as a confidential medical record. A test that measures the ability to perform job-related functions is not a medical examination and may be used earlier.
Does a vendor saying a test is validated protect us?
Not on its own. The guidelines require validation for the use you are making of the procedure, so the relevant question is whether the study covers a job like yours in a workforce like yours. Ask which validation strategy was used, what adverse impact the instrument has shown and in what populations, and whether it has been reviewed as a possible medical examination under the ADA.
Where should an assessment sit in the hiring process?
After a human has decided the candidate is worth time, in most frontline funnels. Every additional completion event is applied to applicants already paid for, and the loss is largest for the most credentialed roles: in our 2026 benchmark 31% of people who clicked a caregiver ad completed an application against 11% for registered nurse roles and 5% for therapy roles. Placing the assessment later applies it to a smaller group with more reason to finish it.
A test filters the applicants you already paid for.
We run employer job ads on Facebook and Instagram and report the cost per applicant with the management fee inside it, which is the number every screening step should be measured against.
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