Subject matter expert (SME): what one does and how to find and vet one

A subject matter expert (SME) is a person with deep knowledge of a particular field or task, shown by their degree, license or years of hands-on experience. Teams bring in an SME when they are building something that has to be right about a topic they do not know well: a training course, a product feature, a technical manual, an exam or a research report. The SME supplies the knowledge and checks the result for accuracy; the team does the building.

Finding one is mostly about describing the exact experience you need. Vetting one means checking that their experience covers your specific question as well as the general field.

What subject matter experts do

Wikipedia's overview gives a useful picture of how the role works in practice (Wikipedia):

• Exams and certifications are often built by a team of psychometricians, who know how to design a test, working with SMEs, who know what the test should cover.
• Manuals, documentation and training are written by technical writers and instructional designers who interview SMEs and turn what they learn into material for the audience. SMEs often sign off on the finished document for technical accuracy.
• Software teams rely on SMEs to explain the domain being modeled, such as accounting, and to validate the finished system, even when the SME knows little about programming.
• Regulated manufacturing can name SMEs formally. The same article quotes the ASTM E2500 standard for pharmaceutical manufacturing systems, which defines SMEs as people with specific expertise and responsibility in an area such as quality, engineering or operations, and gives them the lead role in verifying systems in that area.

In many companies "SME" is an informal label for the person everyone asks about a topic.

A worked example

This example is hypothetical. A small software company is building a feature that helps food distributors close their books at the end of each month. The engineers understand the software; nobody on the team has ever run a month-end close.

They need two kinds of SME:

1. A practitioner: a controller or accounting manager who has run month-end close at a distributor in the last few years, and knows which steps take longest and where errors creep in.
2. A reviewer: someone with the formal credentials to check that the feature's treatment of accruals and inventory is correct.

One person may cover both. Often the practitioner is more useful early, when the team is deciding what to build, and the reviewer later, before release.

Where to find a subject matter expert

• Inside your company. Check whether someone in finance, operations or support has done the job before. It is the fastest route and usually free.
• Your customers. A customer who does the task every day may be glad to review your work in exchange for a product that fits them better.
• Former employees of companies in the field. People who have recently left a role may be able to talk more freely and have more time.
• Professional associations. Some run member directories and committees whose members are recognized in their area.
• Expert networks and paid calls. An expert network will source and schedule SMEs for you. A paid call through a directory works when you can describe the person yourself.

Describe the person by what they have done, not by a title. "Ran month-end close at a food distributor with 50 to 200 employees in the last three years" finds better candidates than "accounting expert."

How to vet a subject matter expert

Check four things before you rely on someone's input:

1. Match to the question. Expertise in a field does not transfer to every question in it. The FTC's Endorsement Guides, which cover expert endorsements in advertising, give a clear example: an "engineer" endorsing a car implies expertise in automobile design, so the endorsement would be deceptive if the engineer's field were chemical engineering (16 CFR 255.3). The same logic applies to your SME: check that their experience covers your specific question.
2. Recency. Tools, rules and practices change. Ask when they last did the work.
3. Hands-on or managerial. A manager knows how a process should run; the person who does it knows how it actually runs. Decide which you need.
4. A specific example. Ask them to walk through a recent instance of the task. Vague answers are a warning sign.

If you plan to quote the SME publicly, for example in marketing, the FTC's guides go further: the expert's endorsement must be supported by an actual exercise of the expertise they are presented as having, including an examination or testing of the product at least as thorough as someone with that expertise would normally need to support the conclusions. Get their review in writing and describe their credentials accurately. This is general information, not legal advice; check advertising claims with counsel.

How to choose the right expert for your first research call goes further on comparing candidates.

How to interview a subject matter expert

• Send context first. A one-paragraph brief with your goal and the decision you need to make lets the SME prepare.
• Ask about real cases. "Walk me through last month's close" produces better detail than "how does month-end close work?"
• Separate facts from opinions. Ask how they know something and whether other companies do it differently.
• Record decisions, not only notes. After the call, write down what you will change because of what you learned.
• Respect confidentiality. SMEs may not be able to share details about their current or former employer. What to do when an expert cannot share confidential information covers how to work within those limits.

If two SMEs disagree, that is useful information. What to do when experts disagree explains how to resolve it.

Your next step

Write one sentence describing the experience your project needs, using what the person has done rather than their title. Then look inside your company and your customer base first, and go outside if nobody fits.

Instant Expert can find people who match a description such as "controllers at food distributors who run month-end close." You review who it finds, it sends your invitations and you pay for each call that gets booked. The directory pages for finance professionals in food distribution and product professionals in accounting software are one place to start.