Either interpretation could be correct, but I'd tend to say that four is too young to know for sure what a child's ability and academic needs may be down the line and brief screening instruments aren't the best way to tell either way.
If possible, I'd defer making a decision and try to have him tested on a more comprehensive measure when he is older and you are faced with making schooling decisions for elementary. Could you afford to have a full IQ test done in a year or so? I'd love to say wait longer (until about age seven or so, when the scores are probably going to be more stable than at four), but if you really need the info to decide for elementary placement, you might have to test sooner.
Also, IQ isn't the only thing that matters in terms of academic placement needs. I've seen kids with less remarkable IQs than the 85th percentile do well in GT programs and with some acceleration and who continue to perform well into middle school as good students in honors classes with top notch achievement scores. I don't think that these kids' IQ scores are wrong or falsely low in these instances. I just think that they are bright high achievers who are motivated and who come from families that place value on their education and achievement. Sometimes those kids do better achievement-wise than the more HG+ kids.
I guess that it comes down to what your alternative to traditional public school is. If the alternative really would not be a good fit for above average very high achieving kids, should that turn out to be what he is, then it would be more vital to know. Our GT programming often is a better fit for the kids who aren't so HG+ so I wouldn't worry terribly about placing a kid who isn't technically gifted in them, should that be what a specific kid was.
