Before hiring an evaluator, ask questions that show how they'll design the evaluation, how they'll share what they learn, and how they'll work with your team. Ask how they'll decide what to measure, how they'll keep the data collection manageable for your staff and participants, when your team will hear findings, how they handle results that aren't what you hoped, what they'll need from you at the start, and who will do the work. Their answers matter less for any single right phrase than for whether they start with what your project needs to learn.
Ask every evaluator you're considering the same questions, and write down how each one answers.
The same questions, asked of each evaluator, show you differences in how they think that their websites and résumés won't.
Choose the five or six questions below that matter most for your project and bring them to your first conversation.
The questions to ask an evaluator about design are the ones that show whether the evaluation will be built around your project or around a method they already prefer.
The questions to ask an evaluator about sharing findings tell you whether you'll hear what the evaluation is learning in time to use it.
The questions to ask an evaluator about working together show you what the relationship will be like for your team over the next several years.
The answers that should make you cautious are the ones that suggest the evaluation will serve the evaluator's routine more than your project. Be careful if an evaluator recommends methods before asking what your project needs to learn, proposes to measure everything, describes the work only as an annual report, or suggests the results will be positive before any data is collected. A vague answer to "What will you need from us?" is also worth a follow-up, because unclear expectations at the start can create extra work for your staff later.
What an evaluator charges is its own question, answered in What does an external evaluator actually cost?, and credentials are covered in Does our evaluator need a Ph.D. or specific credentials?
We don't collect data simply because it might be interesting, and we don't believe more measures automatically mean a more rigorous evaluation. We're not interested in producing enormous reports no one reads.
We also don't tell clients that everything is going wonderfully when the evidence suggests otherwise, and we don't want clients dependent on us to make sense of their work. Those are the answers we'd hope to hear from any evaluator you're considering, including us.
In a first conversation, five or six questions are usually enough to show how an evaluator thinks, especially the ones about deciding what to measure and sharing findings, and you can ask the rest once you're comparing proposals.
Yes, ask every evaluator the same questions, because the differences between their answers are what help you decide. How do I choose between two evaluation firms that both look qualified? covers what to weigh once you have their answers.
You should ask about experience with your funder, and specifically whether the evaluator has worked with your solicitation's evaluation requirements before. Ask them to describe what those requirements mean for the evaluation plan, the timeline, and the reports.
It's fair to ask an evaluator for a sample report, as long as you understand they may need to remove client details or share a shortened example. How clearly the sample explains its findings tells you a lot about what your own reports will look like.