The EVE Personality test is an attempt at creating a "Bartle Test of Gamer Psychology". The Bartle test was developed during the era when "MMO" meant "fantasy role playing" and usually involved an XP grind. While some of its terms are not directly transferable to EVE Online, I think it's worth investigating. Go do the Bartle test, I'll wait here.
Did you notice that there are lots of questions? Overall, in order to sort people into four basic personality types (Achiever, Killer, Explorer, Socialiser) the Bartle test uses 30 questions.
Did you notice that the tests contained lots of annoying dichotomies? That is, questions that forced you to choose between two things that didn't quite gel? Things like, "Would you prefer to (a) get XP faster or (b) solve a riddle none else has gotten" when you know there should have been a choice for "(c) score more kills per week than the other guys". This is part of the exercise: taken out of your comfort zone, which way would you roll? This is also why there are so many questions: between four zones there are sixteen ways to roll, so the questions have to ask you which way you'd tip between any two of the zones rather than giving you the comfort of always choosing the one you know you prefer. And then you cover as many of the choices twice as you can.
So to discern between "Socialiser" and "Killer" you might task questions like: "You meet a stranger on the roadside, far away from any town guards. Do you say hello and see if they have interesting stories to tell, or perhaps a trade tip, or do you run them through with your sword?"
But then you'd ask the question again, slightly differently, "While exploring a new area, you encounter another adventurer. Do you attack them before they attack you, or approach and attempt to chat?"
And of course, you wouldn't ask a question with such a natural dichotomy. The question might be, for example, "While exploring a new area, you notice signs of another adventurer. Do you find them and try to sell them something, or wait in hiding to attack them when they pass?"
So there are 30 questions to cover the four basic personality types in the Bartle system. In EVE Online's personality test, there are 12 personas. The combination of these would be in the order of 144 combinations, multiplied by two to get about 280 questions you'd need to ask in order to determine personality type. The EVE Persona test uses three two-way questions, allowing for a maximum of 16 end points.
One might argue that the EVE Persona test is obviously flawed, since it doesn't have anywhere near enough questions. On the other hand, it's short enough to be within the attention span of a casual visitor, and the distinctions between "Salvager" and "Pirate" aren't really that broad.
What I'd love to see is an expanded in-game version of this running in parallel to the existing "Race/Bloodline/School" selection process: so rather than selecting your race up front, you'd face a small battery of questions such as, "Is it more important to protect the livelihood of your employees, or find new expressions of individuality?" (which would obviously tip the scales along the Amarr vs Gallente axis). Then you'd have your Race/Bloodline/School picked for you, and all that's left is to choose the gender, press the "Randomise" button in the character creator, and get into the game.
Heck, it might even be worthwhile adding channels into the game for "Bartle Explorers" and "Bartle Achievers" for example, so people can get to meet likeminded individuals.
In the meantime, I'm an Explorer type. One of the reasons for picking Vherokior when I started the game was that I liked the description of a nomadic people that populated the vast inhospitable deserts of Matar.