It seems (to me) a good starting point for intelligence would be "the average person." Refining this definition would involve researching all relevant objectiv

It seems (to me) a good starting point for intelligence would be "the average person." Refining this definition would involve researching all relevant objective tests that can be measured accurately, then forming some sort of matrix of comparison. Initially I would pursue the testing on a single interface - using a black box approach with a text interface, then later extending it to other fields (such as movement / navigation, visual, aural etc) If the AI can function on par with the average control, then it could be said that it is averagely intelligent based on the test matrix. NOTE: This is just a top-of-the-head idea, I know it is a lot more complex than I make out (how do you define learning?) but it seems a logical starting point to me. Use current tests and results - just be careful not to feed the AI the original data.