Well, the candidates doing both screens is better, but it doesn't totally solve your problems.
It doesn't address the survival bias issue, and when you say a significant percentage dropped out, that's not reassuring. But it's not the case that you need a lab to solve the problem. Even a basic questionnaire of programming ability self-assessment might tell you if there are meaningful differences in the population that quits your process. At the very least, you should understand and talk about survival bias in your article to indicate you're aware of the issue.
Even if you still want to claim a difference between the quiz and coding exercise, you're not yet in the clear. For example, did you counterbalance the order you gave them to people? E.g., if everybody did the quiz first and the fizzbuzz second, that meant they were mentally fresher for the quiz and slightly more tired for the fizzbuzz, which could again create a spurious result. And this definitely doesn't require a lab to test.
Don't misunderstand me, I appreciate your attempts to quantify all this, and I actually think you guys have roughly the correct result (given the limited nature of fizzbuzz-style coding), but when you step into the experimental psych arena, you need to learn how to properly analyze your data. Given that your business is predicated on analyzing the results of how your hires do in the real world, you need to really up your analytical game.
It doesn't address the survival bias issue, and when you say a significant percentage dropped out, that's not reassuring. But it's not the case that you need a lab to solve the problem. Even a basic questionnaire of programming ability self-assessment might tell you if there are meaningful differences in the population that quits your process. At the very least, you should understand and talk about survival bias in your article to indicate you're aware of the issue.
Even if you still want to claim a difference between the quiz and coding exercise, you're not yet in the clear. For example, did you counterbalance the order you gave them to people? E.g., if everybody did the quiz first and the fizzbuzz second, that meant they were mentally fresher for the quiz and slightly more tired for the fizzbuzz, which could again create a spurious result. And this definitely doesn't require a lab to test.
Don't misunderstand me, I appreciate your attempts to quantify all this, and I actually think you guys have roughly the correct result (given the limited nature of fizzbuzz-style coding), but when you step into the experimental psych arena, you need to learn how to properly analyze your data. Given that your business is predicated on analyzing the results of how your hires do in the real world, you need to really up your analytical game.