At sixteen or seventeen, many people choose a degree, and the degree quietly chooses a career. Usually it's a career they have never watched anyone do for a full day. They choose from a title ("engineer"), a show (every hospital drama ever made) or a parent's hope. It works out more often than you'd expect. It is still a guess.
This piece is about turning that guess into a few small, cheap experiments. The other thirteen pieces in this series each walk through one real job, covering the studies, a typical day, the pay and the downsides. Start here, and you'll know which of them to read first.
A good career sits where all three overlap, and most career mistakes come from answering one question and assuming the other two will follow. You can love biology (interest) and have a great memory (skill), and still be miserable as a hospital doctor if what you need most is predictable evenings (value). You can be brilliant at accounting and bored stiff by it. Keep the three apart while you think, then look for the overlap.
In 1959 the American psychologist John L. Holland published a theory of vocational choice that is still one of the most widely used maps of work interests. He sorted people, and work environments, into six types. Their initials spell RIASEC:
Neighbours on the hexagon are most alike; dashed lines join the least alike.
Your code is your two or three strongest letters, in order. Jobs get codes too. The US Department of Labor's occupation database, O*NET, rates every occupation on all six. Mechanical engineers come out RIC, accountants CEI, and teachers simply S, because the Social score dwarfs the rest.
Good: interests are steadier than you'd think. A 2005 review of 66 long-term studies, following people from age 12 to 40, found that interests become much more stable during the college years (about 18 to 22) and then stay that way for two decades. On that measure they are steadier than personality traits. Your answers at fifteen are a draft. By your early twenties they're closer to a final copy.
Good: fit predicts doing well. A 2012 analysis pooled 60 studies with 15,301 participants. People's interests were moderately linked to how well they performed and whether they stuck with a job or a degree, and measures of fit between person and job predicted better than interest scores alone.
Limit: fit is a weaker predictor of happiness. Reviews of the link between interest fit and job satisfaction find it small, and in some analyses close to zero. How much you enjoy a job also depends on your boss, your colleagues, your pay, your hours and how much control you have.
Limit: interest is not ability. No quiz can tell you whether you'll cope with the maths, the night shifts or the rejection. Those you find out by trying.
Limit: job titles hide very different jobs. "Lawyer" covers a courtroom litigator and a contracts specialist who almost never sees a courtroom. The O*NET code is an average across everyone with that title.
Limit: it's a map, not the territory. The model was developed in the United States. Researchers have found that the neat hexagon fits some cultures less well; one study found an eight-sided model fitted Japanese students better. Quick quizzes like the one below are also rough. For a properly tested measure, take the free O*NET Interest Profiler (60 questions, or a 30-question mini version).
A test can tell you where to look. Only trying the work tells you what you'll find there.
Tap one answer for each activity. Go with your first reaction to doing it regularly, not with whether you'd be good at it. Results update as you go.
How this works. Each answer scores 2 (like), 1 (not sure) or 0 (dislike), and each letter's score is its share of the maximum. The match compares the shape of your six scores with the shape of each career's six O*NET interest ratings (a correlation). It measures pattern, not intensity, and it's a prompt for exploring, not a verdict. Highlighted letters in a career's code are ones that also appear in your top three. Teacher uses O*NET's Secondary School Teachers profile (25-2031.00); Elementary (25-2021.00) is nearly identical and also coded S. Doctor uses Family Medicine Physicians (29-1215.00, SI); General Internal Medicine (29-1216.00) codes ISR. Ratings were read from O*NET OnLine in October 2026.
Two things to notice in your results. First, look at the career that surprised you, the one ranked high that you'd never considered. That's the explorer doing its job. Second, look at the one you were hoping for. If it ranks low, it doesn't mean "don't". It means "find out early whether the parts of the job your answers avoided are parts you can live with."
Match the size of the test to the size of the bet (the "one-way and two-way doors" idea from How to Make a Hard Decision). A degree is a large bet, so place several small ones first, roughly in this order:
O*NET lists what people in each occupation actually do, task by task. For each task, ask yourself: would I enjoy doing this two hundred times a year?
Ask three questions: "What did you do yesterday, hour by hour?", "What do you wish you'd known before you started?" and "Who do you know who left the field, and why?" The third question gets you the most honest answers.
Shadow someone. Notice the boring parts, because every job has some. The question isn't whether a job is boring, it's whether you can stand this particular kind of boring.
A starter project, a free online course or a stint as a volunteer. Each piece in this series suggests specific ones. Doing the work tells you things that reading about it can't.
An internship, a part-time job, a single module or a taster course, all before the multi-year programme.
And give yourself permission to change course. Many people come to the work that fits them by way of something else. Engineers move into teaching, nurses into medicine, history graduates into law. Each piece in this series has a section on where the training can take you, because very few careers are a single locked door.
Keep interests, skills and values separate, then look for where they overlap. Holland's six letters (RIASEC) are a useful, well-researched map of interests. They're fairly stable from your early twenties, and fit predicts performance and persistence. But they say much less about happiness or ability, and a job title hides a lot of variety. Use your code to choose where to look, then test those careers in small, cheap steps before you commit years to one.
Try this: take your top-ranked career and the one you secretly hoped for. This week, read the O*NET task list for each and ask one person who does each job, "What did you do yesterday, hour by hour?"
Sources. Holland, J. L. (1959), "A Theory of Vocational Choice," Journal of Counseling Psychology; Holland, Making Vocational Choices (1973; 3rd ed. 1997). Low, Yoon, Roberts & Rounds (2005), "The stability of vocational interests from early adolescence to middle adulthood," Psychological Bulletin 131 (66 longitudinal studies). Nye, Su, Rounds & Drasgow (2012), "Vocational Interests and Performance," Perspectives on Psychological Science 7(4) (60 studies, 15,301 participants). Tsabari, Tziner & Meir (2005), "Updated meta-analysis of the relationship between congruence and satisfaction," Journal of Career Assessment 13, and later reviews, on the weak fit–satisfaction link. Alternatives to the hexagon (Tracey and Rounds's octagonal and spherical models) and the Japanese–US student comparison, as summarised in Wikipedia's "Holland Codes" article. O*NET Center, Interest Profiler Short Form (60 items) and Mini-IP (30 items). Career interest ratings and codes: O*NET OnLine, retrieved October 2026, for 17-2141.00, 15-1252.00, 19-3093.00, 25-2031.00, 25-2021.00, 29-1141.00, 29-1215.00, 29-1216.00, 47-2111.00, 23-1011.00, 13-2011.00, 17-1011.00, 27-1024.00, 19-3033.00 and 15-2051.00. The 18 quiz activities are this library's own wording, not O*NET items.