Additional scores

The LASS 8–11 reports also provide Stanine scores (ST), National Percentile Ranks (NPR), T-Scores and Z-Scores:

  • The Stanine places the student’s score on a scale of 1 (low) to 9 (high) and offers a broad overview of performance.
  • The National Percentile Rank relates to the SAS score and shows the percentage of students obtaining a certain score or below. An NPR of 50 is average since 50% of students obtained an SAS of 50 or below. An NPR of 5 indicates that a student’s score is within the lowest 5% of the nationally representative sample and an NPR of 95 means that a student’s score is within the highest 5% of the national sample.
  • T-scores have a mean of 50 and a Standard Deviation (SD) of 10, so a T-score of 40 is one SD below the mean and a T-score of 60 is one SD above the mean. 68% of T-scores would fall within the 40-60 range, so a T-score below 40 would be considered below average and a T-score above 60 would be considered above average.
  • Finally, Z-scores show us the student’s score in standard deviation units, with a mean of 0 and an SD of 1. So, a Z-score of -1.0 would indicate that the student’s score is one SD below the mean and a Z-score of +1.0 would indicate that the student’s score is one SD above the mean.

The relationships between these different scores are shown in Figure 27 below. 

 

Figure 27. Relationship between scores

LASS Graph Scores