Interpreting results

The results from Rapid are presented in a way that is very easy to interpret. A table shows the Standard Age Scores (SAS) for each of the subtests. Standard Age Scores, like IQ, are usually expressed with a mean of 100 and a standard deviation of 15. These scores reflect the student’s performance compared to those of the norm referenced group, which is based on the student’s age, in three-month age bands from 4:0–4:2 up to 15:9–15:11.

Any test score is only an estimate of the student’s ability, based on their performance on a particular day. Performance on any test can be affected by several factors. The Rapid report provides confidence bands, which give an indication of the range within which a student’s score lies. The dot on each subtest row within the table represents the student’s SAS and the horizontal line represents the 90% confidence band. The shaded area shows the average score range. 90% confidence bands are a very high-level estimate; if the test were taken again, we would expect the score to fall within this range 90% of the time.

The Rapid report identifies SAS scores of 88–94 as being ‘Slightly below average’, SAS scores of 75–87 as ‘Below average’ and SAS scores below 75 as being ‘Very low’. As such, action is recommended where SAS scores are in any of these ranges and the Rapid report will refer the tester to the Indications for Action table on the GL Ready Support website (, where appropriate. The GL Ready Support website can be accessed via the ‘Help’ button on the GL Ready website.

Figure 16. Example graphical student report

The results of the three subtests are combined by the program to arrive at an overall probability of dyslexia, which is also shown on the reports screen. This is achieved by means of an algorithmic expert system derived from research data. The overall probability cannot be worked out until the student has completed all three subtests.

The expert system gives an overall estimate of the probability of dyslexia in one of the following categories:

● High probability of dyslexia (greater than 90% chance)

● Moderate probability of dyslexia (greater than 75% chance)

● Low probability of dyslexia (less than 10% chance).

Additional scores

The Rapid 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 17 below.

Guidance for interpretation table

Figure 18. Example of the Guidance for Interpretation section of the report

The Guidance for Interpretation table on the report provides enhanced guidance for interpreting each student’s results. Match the guidance to the Rapid Indications for Action Table, found on the GL Ready Support website (

Interpreting the results from Rapid requires interpretation of the overall profile, and not just consideration of each individual subtest separately. Please see the Case Studies chapter for further guidance on interpreting the whole profile.