Series: Work Sample Tests
Work sample tests are an exercise, a simulation, a small slice of real day-to-day work that we ask candidates to perform. They’re practical, hands-on, and very close or even identical to actual tasks the person would perform if hired. They’re also small, constrained, and simplified enough to be fair to include in a job selection process.
Work sample tests are a critical factor in effective hiring. Interviews aren’t enough; hiring without work sample tests risks selection people who excel at interviewing but can’t actually perform the job.
This series builds a framework for effective work sample tests, and gives a bunch of examples of effective tests.
Earlier this year, I wrote a series on interview questions. Good interview questions are one key to hiring well, but they’re not the only key. Today, I’m starting a new series on another critical factor in effective hiring: using work sample tests, aka practical exercises. This is part 1: what are work sample tests, and why do we need them?
Good hiring processes try to maximize inclusivity and predictive value, but unfortunately, work sample tests bring these goals into conflict. There’s always a tradeoff between predictive value and inclusivity. The guiding principle of work sample tests is: construct a test that balances predictive value and inclusivity. Fair work sample tests will be predictive enough to give you a high degree of confidence that you’re making a good hire, while also being designed to be as accessible to as many candidates as possible.
What makes a work sample test “good” – fair, inclusive, and with high predictive value? Here’s my framework: eight principles that, if followed, give you a great shot at constructing a good work sample test.
Work Sample Tests:
Coding “Homework”
November 23rd, 2021
Coding homework is my default work sample test: I use it for all engineering roles unless it’s obvious that another kind of exercise is better. There are good reasons to make homework-style work sample tests the default: they’re relatively easy to construct, they scale reasonably well to large hiring rounds, they’re accurate simulations of real work, and easier than most other kinds of tests to construct in a way that maximizes inclusivity. Here’s how to conduct a coding homework work sample test.
Work Sample Tests:
Pair Programming
November 30th, 2021
I tend to prefer asynchronous work sample tests. The flexible scheduling of asynchronous exercises (i.e. “work on this whenever you like”) works better for the majority of candidates. But for some candidates, and some roles, synchronous exercises work better. By “synchronous” I mean: work sample tests that are explicitly scheduled, and that has both the interviewer and the candidate working directly together at the same time. In these cases, I often turn to pair programming.
If you’re hiring engineers, some candidates will already have code they can share: side projects, open source, and so on. It’s silly to ask those candidates to write new code just for your interview if they already have code they can share. So, if you’re asking candidates to code as a work sample test, you should also offer to let candidates submit something they’ve previously written. Here’s how.
For most software engineering roles, the best work sample test will be some combination of the exercises I covered earlier in this series. But not every role; there are some circumstances where other types of tests fit better or are better at revealing some critical piece of information relevant to hiring. This post covers one of them: a “reverse” code review, where instead of you reviewing the candidate’s code, you have them review yours.
The work sample tests I’ve covered in this series so far all involve software development. But what about roles that don’t involve day-to-day coding: roles like security analysis, penetration testing, technical support, bug bounty triage, project or program management, systems administration, technical operations, and so on? For those roles, I turn to simulated, “lab”-style environments. Here are some examples of that kind of test.
I’ve written about a bunch of effective work sample tests and the “rules of the road” that make them effective. One thing I haven’t talked about is counter-examples: types of work sample tests that don’t work. I tend not to do this sort of thing: I find it’s usually more useful to talk about what does work than to pick apart what doesn’t. But here, I think it’s illustrative: looking at why certain kinds of work sample tests fail can help illustrate the principles of effective tests. Let’s look at a few kinds of work sample tests that (usually) fail, and why.
Work Sample Tests:
Wrap Up and Q&A
January 6th, 2022
This is the final post in my series on work sample tests. It’s a wrap-up post: I’ll address a few random points I couldn’t quite fit in elsewhere, and answer some questions from readers.