To be perfectly honest, I would say that your IQ score isn't the best thing to go by (even for a topic such as this one); there are too many other things to consider which IQ testing does not even come close to addressing. Since I haven't taken an official test, I would estimate my IQ to be ~130 (+2 s.d.); the last online test I had taken gave me a score of 153 (about +3.5 s.d.), which I suspect was inflated.
What I do consider a better indicator of my intelligence is my academics, in that I'm studying engineering; that alone gives me confidence in my vote of "above average". I could've easily claimed "way above average", but erred on the side of caution because I'm well aware of the fact that there are many things I don't know. Nevertheless, I place most of my confidence in my ability to learn anything I choose. Unfortuantely, my chronic motivation issues make me a lousy student; though I do seem to be improving in that regard.
Anyhow, marks & scores are not the best indicator of intelligence. At best, it just means you're a good student; regurgitating knowledge and doing simple problem solving can only account for so much. It's your ability to analyze and apply to knowledge to unfamiliar situations which shows real intelligence, and for the most part it's just the basic application of logic... and maybe a bit of visualization. Practical experience plays just as large a role here (if not larger) as the knowledge gained from a textbook.
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In the end, it boils down to these three questions:
- What is the problem?
- Why is it a problem?
- How do you solve it?
The level of difficulty in those questions can vary greatly, but for the most part it boils down to basic analysis. Design is a little trickier, which is why the second question is there; to see if you really know if you know what you're doing, by knowing why you're doing it.