IQ is just a score on a test relative to the "norming" population. Then IQ is correlated to other things in longitudinal studies like getting a graduate degree.
When they norm a test, they tend to make sure that the group doesn't have prior exposure.
So, with no prior exposure a kid can easily make a mistake here and there from not understanding. Another question here and there can be lost to impulsivity. It can also take a bit to get some kind of solution heuristic.
At a base level familiarity and some training with the sub-test types can reduce some of those errors and thus artifically bump scores. Some verbal aspectds depend on vocabulary richness which is teachable as is a certain amount of numerical reasoning.
Meta-skills like reviewing your work, pre-training in specific solution heuristics, etc. could improve scores.
I imagine there is a limit to the bump prep could give, my gut says maybe 10-15 pts. It would likely level out if there was future testing.
