Calculator for Alternative Norms

Use this tool to compare your client's score on a particular test with published population norms, which may be different from those in the manual (e.g. specific country/cultural norms). You will need the appropriate mean and standard deviation from the published norms, as well as reliability data (see below).

Normative Mean

Standard Deviation

Observed Score

Reliability Coefficient

▼ Which reliability figure should I use?

Please enter the best available reliability data, preferably from the test manual or otherwise from wider research literature. Textbooks such as Sherman et al. (2023) also include extensive summaries of test reliabilities.

Where possible, test—retest reliability is most valid, as it reflects score stability over time.
For memory-type measures, which can be significantly affected by practice effects, measures of internal consistency (e.g. Cronbach's Alpha/Split-half reliability) or alternative form reliabilities may be more appropriate.

Results

Important Interpretation Information:
Percentiles scores are quoted to aid interpretation only, we would urge significant caution in reporting these values. Percentile calculations require the assumption that the scores are normally distributed, which may or may not be true. For this reason, we recommend giving broad ranges rather than specific individual values.

Similarly, confidence intervals are estimated around the Estimated True Score, which is calculated using the reliability data you have entered. The more accurate the reliability data entered, the more accurate the estimated range.

Suggested Reference Sherman, E., Tan, J., & Hrabok, M. (2023). A compendium of neuropsychological tests. United States: Oxford University Press