Instead of an average, you'll find percentile rankings. A percentile ranking indicates the percentage of students who scored at or below a particular score. A score in the 50th percentile would mean the student scored better than 50% of other 9th graders who took the test. Many selective high schools will look for students scoring in the higher percentiles (75th, 90th, etc.).
To get a better understanding of what a "good" score is, you need to:
* Check the specific school's website: Each school receiving ISEE scores will have an idea of the range of scores their admitted students typically achieve. Look at their admissions data or contact their admissions office.
* Consult an ISEE prep company: These companies often have data on average scores, though again, this will be a general range, not a precise average.
In short, there's no single number to answer your question. You need to look at the context of the schools your child is applying to.