First, I tried to find a definition of intelligence and, not surprisingly, found that there are many definitions of intelligence out there. Legg and Shutter (2006) have analysed them and come up with a list of common features and a formal definition:

“Intelligence measures an agent’s ability to achieve goals in a wide range of environments. Features such as the ability to learn and adapt, or to understand, are implicit in the above definition as these capacities enable an agent to succeed in a wide range of environments.” (p.8)

I would imagine then that an intelligence test would measure the ability of a person to solve problems in different environments. I guess the ability to learn and adapt is measured by repeating the test at different times. On the other hand, a knowledge test will check what we have learned about a certain topic. I guess maybe the driving test (theory) would be a knowledge test. 

 I found out that current intelligence tests (e.g. used by Pearson)are based on the Wechsler -Bellevue test, created by the psychologist David Wechsler in 1939. The test used the point-scale system, which gave credits to correct answers (as opposed to Binet's test which would not give credit at all if all the items of a task had not been answered correctly. It apparently also, unlike Binet's test, included a non-verbal performance scale which addressed the biases caused by culture, language or education (Wikipedia). There are different versions of the test according to age and it is also used by doctors to estimate someone's cognitive abilities after suffering brain injuries. There have been different versions created and the most recent one is the WAIS 4. This test seems to have quite good research backing, and I'm sure it is useful to detect learning disabilities (as Stephen Jay Gould was saying in the video in this course). It's difficult to see if this test is good or not as apparently you need to have someone trained administering the test. Online tests might not be a good reflection of the real test. At the same time, it seems that some questions are geared towards vocabulary, which might be more about knowledge. I also think that it might not consider social intelligence which I understand to be the ability to communicate with others. 

Intelligence is so complex and I'm sure the definition of intelligence will change in the future.