The Limber Lambda

Today we assessed our 20^th candidate for position of senior developer, using a small test that I drafted some time ago.  Since then I’ve spoken about how the test was dumbed down since one of the questions was perceived as being too difficult.  The assessment consists of three questions, which I’ve dubbed Fibonacci, Quicksort and University.  I’ve already discussed two of the questions, namely Quicksort and University.

Although not an earth-shattering sample, 20 is a number that we can start to draw pretty graphs with, so I’ve included a summary of the results alongside.

We can speculate about what it tells us:

1. There’s something wrong with University; nobody has come up with a satisfactory answer;
2. In the case of Fibonacci, there’s something wrong with the candidates; only five people have come up with a satisfactory answer.

Ok, my second conclusion above is possibly a little harsh.  I think it’s a little harsh, because upon inspection by others, it’s elicited use of some power words like “mathlete” and “math-wiz”.

Now Fibonacci is the only question that I haven’t posted for all to see, mostly because I thought it was too simplistic and therefore quite uninteresting.  Given these results though, I’ve been prompted to reword it completely.  I mean, if only math-wiz’s have what it takes to do it then I can’t make any assumptions about the background that a candidate may have in the arithmeticmaths department.

What follows is the version of Fibonacci as it was up until now:

I’ve taken great pains to remove anything that may constitute an implicit (read “unfair”) assumption about mathematical background and I’ve reworded the question to provide a lot more hand-holding for the candidate.  This should also help in offsetting the nervousness factor.

Here’s my updated version: