If Simon scored at the 80th percentile on a standardized reading achievement test, what does this indicate?

Scoring at the 80th percentile on a standardized reading achievement test means that Simon performed better than 80% of the students in the norm group who took the same test. This percentile ranking indicates a strong level of achievement in reading compared to others, suggesting that he is among the higher-performing individuals.

Understanding percentiles is crucial in interpreting standardized test scores; the 80th percentile specifies that 80% of the test-takers scored lower than Simon, while only 20% scored higher. This can provide significant insights into Simon's reading abilities, showcasing that he excels in this area compared to the majority of peers.