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How Effective are Technical Interviews?

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Re: How Effective are Technical Interviews?

#51

Post by orev »

Having been on the interviewing end of a number of interviews, I definitely have found that these types of "quiz" questions ARE EFFECTIVE, to a point. The number of people who claim to know something, but actually don't, are astounding. You'd like to think that people are honest, but they are not.

The main issue is that of time. Interviewing people is an enormous time sync, and spending time to get to know them and their thought process is a complete waste if they don't know the material. Quiz questions can easily weed out the people who claim to know things but don't, and save you a lot of time.

However, quiz questions should not be the only way to determine if someone is good for the job, and you always want to delve deeper with other kinds of questions as well. You can also use the quiz itself as a jumping off point for deeper discussions, which give you insight into thought process, etc...

Re: How Effective are Technical Interviews?

#52

Post by lsb »

Silhouette wrote: post #48
lsb wrote: post #19

Earlier quoted context omitted.

It sounds like the AJAX web app was designed to test your sense of taste and your ability to get things done, and the Javascript question was to test whether you've ever done anything numerical in JS. ('4'+4)-4 is 40, whereas (4+4)-4 is 4. There are a lot of people who glue a few things together in Javascript and PHP and call it a day, and their filter against those is imperfect. Interviews as a whole are less inform…

> and the Javascript question was to test whether you've ever done anything numerical in JS. It's a lousy test, then. The fact that someone can't tell you the answer to that question, off the top of their head under interview conditions, might mean they are a newbie claiming to know languages they really don't. However, it could also just mean that they have experience with several dynamically typed languages but, si…

Of course it's a bad test.

Google says they only hire people above the mean skill level of a Google engineer, so you need to look better than an average Googler to get in.

http://googleresearch.blogspot.com/2006/03/hiring-lake-wobeg...

Re: How Effective are Technical Interviews?

#53

Post by jcs »

tptacek wrote: post #39
sophacles wrote: post #25

I have found that for technical interviews, the following pattern works very well (hiring side): 0. Explain to the candidate this algorithm and why. It isn't magic, there are no right or wrong answers, just testing "fit". This is a case where foreknowledge does not change the outcome! 1. Get a basic grasp of technologies both interviewer and candidate have in common, via say, just chatting. This is vital -- find an a…

I have over the last 8 years or so become terrified of interviewing techniques that revolve around having a conversation with a candidate, even (or, in fact especially) directed conversations. Like many others before me, I've discovered that there is a huge gap between the ability to talk intelligently and productively about solving programming problems, and being able to actually solve programming problems. It's fin…

    and watch them code something
You may find http://www.interviewzen.com/ useful. It's a hiring tool I'm building around the idea that you can tell a lot about someone's coding ability by seeing them in action.

Re: How Effective are Technical Interviews?

#54

Post by kscaldef »

dkarl wrote: post #49

Many technical interviews are very theory-heavy, muddling the divide between Computer Science and Software Engineering. I've been faulted for this in my interviewing, but I think that you have to pose at least one problem that can be explained precisely in less than a minute and solved completely in less than an hour. Such a problem will inevitably have an abstract, theoretical feel. It's also good to ask more realis…

In my experience, people start complaining that an interview is "theory-heavy" at about the point that you expect them to know when and how to use a binary tree. Binary trees are not hard-core CS theory, they are freshman Intro to Data Structures. They are a very basic tool (almost) every programmer should be familiar with.

Moreover, when I ask candidates questions about data structures and algorithms, while it's nice if they can ace it all without hesitation, what I'm really looking for is what happens when their first answer is wrong. When they pick an incorrect data structure for the problem and I probe to say, "so, using that data structure, how do you this task?", I want to see if they will realize that the task I'm asking for is hard to implement or has very poor performance using the data structure they have chosen, and whether they will step back and realize they made a mistake. The point is less what do you know, but do you know what you don't know and do you recognize when what you're trying isn't working.

Re: How Effective are Technical Interviews?

#55

Post by agentultra »

I like the approach in this post. It sounds more reasonable.

I dislike the term, "screening." It's not a good feeling for the interviewee to know that they're just being filtered before they get an interview. That the person interviewing them doesn't even believe that they can do their job properly. Screening reinforces the notion that the interviewee is just another rat in the race and that you, the interviewer, barely have the time to see them. It's an ugly, loaded term and I really don't like even hearing it.

The traditional hiring process is a problem that goes both ways. It's nerve-wracking and emotionally draining for the person being interviewed and it's a time consuming risk for the person interviewing. The interviewee has to spend time crafting their CV, prepping themselves to answer a slew of random esoteric and useless trivia, and drag themselves to countless appointments. The interviewer has to sift through innumerable resumes and figure out which ones fit, sit through dozens of interviews, and then gamble that the person they've selected isn't going to waste a whole bunch of time and money.

I think it's a search problem. At least for hiring programmers I think it's possible to filter incoming applications to your specific requirements. It should be possible to rank those submissions within your query. Then you should already have a good idea of how many interviews you will need to do and you can skip past the "screening" process.

At least, I hope. I've been putting some back-40 hours into figuring out this problem. :)

Re: How Effective are Technical Interviews?

#56

Post by eftpotrm »

jswinghammer wrote: post #12
tomh- wrote: post #11

Earlier quoted context omitted.

What is the question I may ask?

Implement: itoa

Heh, an ex-employer had an even simpler filter we used :-)

We had a 2 page tech test and did read it all, but most of the time we could mark it based on the first question. For a VB+SQL job, most of the candidates couldn't write a valid INNER JOIN statement.

Oops. Bye.

Re: How Effective are Technical Interviews?

#57

Post by chollida1 »

shortlived wrote: post #26
tastybites wrote: post #21

We hire people based on enthusiasm, general intelligence (you can usually tell after a few minutes) and a low level of demonstrated proficiency - we'll ask them to explain a code sample they wrote, or ask for a verbal description of how to solve a problem. We choose the person we like best, and if they don't work out after 2 weeks we fire them. Hot seat quizzing produces way too many false negatives. We are not googl…

Are there laws that allow/prevent the 2 week trial period for a business?

I'm Canadian, but here most, almost all, companies have a 3 month window in which a new hire can be let go without severance.

Re: How Effective are Technical Interviews?

#58

Post by michaelcampbell »

I haven't found them to be particularly useful except as a level 0 filter - you can get rid of some very shoddy people early, but finding the actual gems they do very little (in my experience, anway).

I don't know who started this practice but it seems a lot of interviews recently are the brainteaser type; how many ping pong balls fit into a 1974 Super Beetle (hardtop), etc. Those are the worst.

Re: How Effective are Technical Interviews?

#59

Post by [deleted] »

fendale wrote: post #22
jswinghammer wrote: post #12

Earlier quoted context omitted.

Implement: itoa

I had to lookup what itoa is not being a C programmer. Which got me interested - how would you implement this? My inital thought is to do something like (in pseudo code): str = ''; while (i > 0 ) { # least significant digit r = i % 10; # throw away the least significant digit i = i / 10; case when r = 0 then str = '0' Would I pass with that? Is there a better way?

[deleted]
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