In previous posts, I’ve talked about the most important types of interview questions:

‘Behavioural’ questions ask ‘Describe a time when you encountered a problem like this’.

‘Situational’ questions ask ‘Given this situation, how would you solve it?’

‘Technical’ questions ask ‘Solve this defined problem for me.’

Today, I’ll cover some other types of questions that are known to not have much predictive power, but people still ask, either as an ice breaker, or because they have other reasons for asking these questions.

‘Ice Breaker’ questions ask ‘tell me a story about yourself, to help relax you.’

The purpose of ‘Ice Breaker’ questions is to get the conversational flow started. My personal favourite is ‘tell me about the project you’re most proud of’, because it will help to relax the candidate, and has the dual purpose of showing what a candidate is like when they’re excited about something.

‘Dumb’ questions ask things outside the normal boundaries of a standard interview.

From the link, examples might include “What kind of animal would you like to be?” or “What color best describes you?[1]” The ostensible purpose is to try to get beyond pre-programmed/rehearsed answers, looking for original thoughts. (I tend to prefer the ‘tell me what you’re most proud of’ type of question, as if you’re trying to knock a person off their rehearsed interview game, if they’re nervous, that might torpedo them, and you’re torpedoing them based on their interview skills, rather than actual skills. Better to choose a topic they know, and explore the limits of their thinking there.)

‘Illegal’ questions ask ‘I want to discriminate against you, in some illegal way’

Which questions are illegal will vary by jurisdiction, but generally include questions about things such as gender, age, marital status, religion, etc… Larger and governmental organizations tend to be better at not asking such questions, whether because of visibility or lawsuits. Knowing how to answer such questions can be tricky, because of the power differential between interviewer and interviewee, but especially because the organizations asking such questions may be hiring from a labour pool with few options.

‘Brainteaser’ or ‘Fermi‘ questions ask ‘How many piano tuners are there in New York’?

These questions are the stereotypical ‘Google interview’ question, which is funny, because Google no longer asks this type of question[2]. I happen to enjoy this type of question, and they can be very useful for back-of-the-envelope estimation, but don’t really have a useful place in job interviews.

Next time, we’ll go more in dept about specific types of technical questions. Stay tuned!

[1]My favourite story on this topic comes from the brainstorming exercise: “List all the things you could do with this brick.” People would come up with some small number of ideas (like <10) for how to use the brick. Then the facilitator would say something like: "List me all the ways that your wackiest friend could use this brick." Interestingly, this generally elicits many more ideas, as it removes some of the social opprobrium of being 'weird'. [2]cf. The British Empire no longer uses the ‘Imperial’ system.

I’ve been writing about interview questions recently, most recently about ‘behavioural’ and ‘Situational’ questions. If you recall:

‘Behavioural’ questions ask ‘Describe a time when you encountered a problem like this’.

‘Situational’ questions ask ‘Given this situation, how would you solve it?’

‘Technical’ questions ask ‘Solve this defined problem for me.’

Today, I want to talk about ‘Technical’ questions. This includes two types:

‘Problem Solving’ questions, where the interviewer asks a technical question, and expects you to go through some process to solve it, similar in some way to what one would do in a job in the field.

‘Knowledge’ questions, where the interviewer asks specific questions about your field of study or work. For a programming job, they might be about memory management or data structures, for HR, they might be about what is legal or accepted practice in the jurisdiction in question, etc…

(Note that these generally don’t include questions about a resume, which I would group under the ‘Behavioural’ umbrella, as the interviewee is expected to tell a story about them.)

So what is an interviewer looking for in these questions?

For both of these questions, the interviewer is looking for command of the subject matter and problem solving ability. There’s a whole smear of possible questions between these two extremes. (‘What is an array’ to ‘Design LinkedIn’.)

For basic knowledge questions, it would probably suffice to re-read a textbook, or read (and understand!) a glossary of the topics one would be interviewed in.

For ‘Problem Solving’ questions, answers are generally more involved.

Generally, the interviewee is given a problem statement:

“Write a program which counts from 1 to 100, and outputs ‘Fizz’ when the number is a multiple of 3 and ‘Buzz’ when the number is a multiple of 5.”

This problem statement may or may not be well defined, so it falls on the interviewee to ask questions until it is adequately defined:

“Does it also print the number when it is a multiple of 3 or 5?” “Is proper syntax required?” “What language?”

(This also makes sure that the interviewer and the interviewee are on the same page.)

I like to draw a large diagram, and/or write down my assumptions in the upper-left corner when doing problems like this. Makes things explicit, people can see what you’re thinking.

One of my best bosses described his best programmer as ‘having a reason for every single line of code’. Talking through one’s code as it’s being written can help with this.

So:

Write down assumptions
Draw a big diagram
State the overall algorithm
Write down the solution, while talking about it
Think about corner cases, run an example through in your head.

Next time, we’ll talk some other types of questions, the kinds that are known to be not as predictive, but that interviewers still ask anyways, for various reasons. Stay tuned!