For this sort of test, all that is necessary is that you understand the basic idea of a for-loop...the basic idea of how to format a string...remember there's a good chance you're writing in pseudo-code.

Presumably however if you are a programmer, there is at least one language where you should be able to complete this task without looking anything up. It requires only the simplest of language constructs/library functions.

The exception of course is if this is a job for say, a Python programmer...and on your resume you say you are a "Python expert". The fact that you have to look up the syntax for basic constructs in Python would suggest you were lying on your resume. That's one of the things this exercise tests for.

If you said in your resume "I have experience with other languages, but I can learn Python"...then just being able to do this exercise in pseudo-code or any language of your choice would show you have basic programming skills and should be able to pick up Python.

If you really have to remind yourself what a for-loop is then yes, maybe you do have to go back to school/hit the books and study harder.

You see that's the crux of the issue, I can be a JavaScript expert and deliver massive JavaScript applications without having to resort to the arguments array to figure out how many parameters where passed into a function. Also, if I ever had a use case for it, I would look up the API and probably mentally discard it shortly afterwards. The interviewer thought that it was a perfectly reasonable filter, but yet I am one of the top JavaScript talents in my market. It did not work for them, because they assumed that knowledge of the arguments array was basic knowledge and any developer worth their salt would know it. Yet in my time working with some great JavaScript developers not a one of us ever used it. Further it harmed them because I now believe they are as incompetent as they believe me to be, as such if someone in my peer group asked about a position with them, I would relay my story. Not to be indignant but to be truthful, as such they lost access to valuable resources in a constrained market.

That being said, one can be an expert in say Java and not know the JDBC API, maybe all of their work revolved around JPA. Many in Java would argue that JDBC is fundamental and should be known to be an expert but a new crop of developers have never know anything but ORM. But we older developers assume that JDBC is a fundamental prerequisite because it was in our time. They cant see anything but the progression from JDBC to JPA because it is the life experience that they had. As such it's flawed and irrelevant. You have to be very careful to not bring interviewer bias into an interview and test are loaded with them. Even the simplest of test.

Does it not strike you that quite a few HN'ers openly admit that they would not pass the filter? Some of them long time contributors and members, some of them very respected? To me, I would question the viability of my assumptions if HN'ers where openly saying no your filter would eliminate me. I mean we have some of the best of the best lurking here. 37 has been complaining about it for a long time, I have had my own threads about it, and everyone agrees that hiring is flawed. Maybe it's time we reevaluate our assumptions based on what guys like the crew at 37 are doing since they seem to be improving on candidate selection over the rest of us.

The point I am making is what you are trying to garner, can be identified by asking a candidate to show you something they built and walk you through the routine they are most proud of. There are going to be functions, loops, if statement etc. in that code, if they can't explain what they built, then you should be suspect. Giving them a test just introduces bias of what the interviewer thinks they should know, and does nothing to tell the interviewer what they know.

To be quite honest, this thread is having the opposite effect. I'm questioning the quality of HN contributors based on their inability to either comprehend the question or code a simple algorithm.

I passed similar coding questions in interviews before I'd ever written a line of code in my life (in a Microsoft PM internship interview). No one cared if I wrote a semicolon or not - the interview was asking if I understood basic concepts like loops and logic.

I have yet to see someone who says that they would not pass the filter. Every single example I've seen in this thread is someone making up a different filter and saying that they would not pass that. I see people saying that they took a long time to debug subtle bugs in it, that they don't know the definition of the problem, or that in general they need documentation to code, all of which is completely irrelevant to the filter as given. Subtle bugs are allowed, the definition is given to you, the solution doesn't need any documentation (and if it does, you can just make up whatever API call you expect would be present in a sane standard library)

I'd be shocked to find any good programmer who, given the definition of Pascal's triangle, couldn't produce some decent, possibly buggy, incomplete, and syntactically incorrect, code on a whiteboard to print out a row from it.

I've yet to see anyone give an argument for how a good programmer could fail this test that doesn't rest on some feature of the test that doesn't actually exist.

You are now hitting at the core of the issue, to most developers bugs, bad code, correct API's matter, you are asking them to look past something that is engrained in their work ethic, personality, and quality as a developer to measure their worth as a developer. It does not matter what the filter truly is, their is a perception on the developers part of what they are being tested for, because they attribute what makes them of value to the test. As such the correct solution is what makes them valuable. You can't tell them to give you what they perceive to be the incorrect solution and expect it to accurately reflect what they value in themselves as a developer, that the interviewers bias. The fact that the filter is being misinterpreted is irrelevant or very relevant depending on your perspective. To the interviewee, they are going to perceive the task just as many on HN have and no amount of prodding to give up their nature is going to make them perform well, conversely they are going to perform worse. I have neglected the fact that the filter is being misunderstood for the very fact that, it will be misunderstood and for that alone it sets people up to fail.

This is one of the point that I am getting at, you are right it's not just the code that is being judged, candidates know that too, so when they are standing at the whiteboard a million things about being judge may be going through their mind. It has nothing to do with being stodgy or honorable or above the effort and everything to do, with some people just cannot perform in such an environment. People hold out that it is a negative filter, that if you can't pass it, you are a definite negative and observations on a lot of peoples parts are not confirming that assumption. I side with the author of the article that there is an all inclusive way to identify good candidates that fall into this category as well as candidates that would pass the whiteboard test without resorting to the whiteboard. I am not arguing that people should not be able to code, rather I side with the author that there is a better way to identify the people that can and receive more positive hits in the process. Thus reducing the interviewing cycle and identify more talent in a constrained market.

I see where you're coming from. I think the issue is that 99% (100%?) of all HNers would likely be great hires for most companies, so they see these questions as trivial, dumb, and not representative. Just the fact that someone thinks about these types of questions and reads programming blogs probably puts them ahead of most of the programming population.

The problem is that many of us have really never seen the mythical horrible programmer. The person that really can't even start a solution to FizzBuzz. The one that leaves the interviewer wondering how the person got jobs at other companies. I have seen and interviewed them before and it's frightening and uncomfortable for everyone involved. I've had candidates break down crying when I asked them to write a simple sql select statement on the board because their resume said expert in sql. For many, it's hard to fathom these people are out there, but they do exist.

FizzBuzz style questions are really important (eg. create an array with 4 numbers: 1, 2, 3 and 4 and output the values. Oh a "Java and Python 'expert'?". Please in both languages then!). Although I agree that home tasks and trick-algorithm questions are useless.

I don't think home tasks are useless, but they have to used properly. A home task geared to 1-2 hours seems reasonable for an exercise between the first and second interview. Some may say they'll just look up the answer (it's encouraged!), and that's why during the second interview the employer should discuss their answer. If the candidate can explain why they made particular decisions on the take home piece and have an intelligent discussion about the trade offs they took then who cares if they looked up the answer. In fact, the home test is probably closer to real programming since I don't know anyone who codes without Google nearby.

So, my preferred method is to use FizzBuzz as a first cut on the first interview and then give a take home quiz that should take the candidate 1-2 hours or less if they are good.