I'm a professional writer; i.e., I get paid to write. I didn't study journalism but I was in an interdisciplinary programme that consisted of literature, history, and language (somewhat of a modern day philology degree) in Canada. I've just recently started to learn how to program.

I think if this hiring process works for you, great! But as someone who recently started learning to program, I must say writers are vastly different from developers.

There are different kinds of writing. A novelist and a poet (and maybe even an essayist) cannot write business letters. Business writing is vastly different from any creative writing, an SEO writer is neither a creative writer nor a business writer, and so on and so forth. The difference between business writing and creative writing is each follow different rules. That is, each discipline gets away with different things. Creative writing exploits language any which way possible to get a point across, even if it means breaking the rules. Business writers are conservative writers. They follow grammar rules closer, as well as orthography. Most contemporary creative writers use post-structuralist techniques when telling a story; e.g., levels of narration that go from a protagonist to a secondary character to the world in which the book takes place to a far more omniscient narration and much more (narrative modes can get extremely complex). And if they don't, it is almost a given that a type of meta analysis of it is acceptable and encouraged (nowadays, especially). I don't mean to be condescending but business writers use a more primitive form of writing: straight to the point, the nitty-gritty, the meat of the matter. Business writers specialize in a different form of writing. They have more in common with journalists in that they do not exploit language, but seek the simplest form to explain a concept and be completely understood with no room for misinterpretation. I've always said half-jokingly that journalists aren't writers, because they deal with facts and events. I say this meaning journalists do not explore the frightening realm of creative writing, they only dabble in it. Few have ventured to write creatively within their pieces or let abstract concepts permeate throughout an entire piece. For me, journalists and business writers are data-driven and are hard empiricists. There is no market for creative journalists in the entire sense of the word "creative". When companies say "creative" they mean "Can you come up with an idea in which our audience is interested?"

The proof is actually in the tasting. You say you ask your potential hires to <i>spell</i> out a word. There is your first mistake. Do you know how many great writers were poor spellers? Rarely have I seen great writers who are also great spellers. Great writers have great ideas. This is why the world invented editors. It is an old cliché, but one that is true. What's more: do you know professors still teach and believe this? Right, this isn't Academia, and this brings me to another point. Those who do not major in journalism learn to write differently. Most of my peers were bad writers, but they might be a perfect match for a business's needs because they abide by the parameters set by the company. This brings me back to the point that in most business settings, people do not want creative writers. They want someone who writes within the parameters the business calls for or the higher-ups assign.

The Oxford comma. How much does a writer gain by knowing a definition of a word? Let me expand on what Richard Feynman said about what things are called: "I learned very early the difference between knowing the name of something and knowing something". Definitions belong to the category of "knowing the name of something". The problem with this type of 'knowledge' is, most of the time, the interviewer, as someone unfamiliar with the mechanics of language, does not have the capability to ask and know what function the comma holds when placed in a list before a coordinating conjunction. You are testing how many words a writer knows. So, you might as well ask what a Harvard comma is, just in case, to test if the hire knows this and many other words. Anybody can be a technical writer. Anybody can learn the simple rules of language enough to convey a comprehensible idea.

You're essentially looking for a person who fits your idea of a good writer, which should be understood as being a subjective notion. You have a process for knowing who can write best sellers? What are you waiting for? There is lots of money you can be making and, as I'm sure you are a man of science, you can test your hypothesis of being able to pump out best-selling writers.

Seriously. No. Writing a best seller is a completely different ball game, but please feel free to prove me wrong by giving me some results.

Also, I'd just like to clarify that I've not even touched upon the nuances and differing grammar rules from the US, Canada, Australia, and the UK. Suffice it to say that comma splices are not always incorrect depending on where you live and there are different rules for comma usage.

Also, the Elements of Style is an archaic and misguided book, for the most part. None of my professors ever stressed its importance or use. Unfortunately, I've run out of time and must go now. I wish I could touch on other points!

Sorry for any 'style errors' - I've not proofread this :P