---
title: "t-scores"
description: "I probably last saw this in the last century but I'll put it in anyway! #### Details Essentially another standardisation method but transforms raw scores so their mean is 50 and one standard deviation is 10. So the equation is:…"
url: "https://www.psyctc.org/psyctc/glossary2/t-scores/"
updated: "2024-04-03"
category: All OM book glossary entries
---

# t-scores

I probably last saw this in the last century but I'll put it in anyway!

#### Details

Essentially another standardisation method but transforms raw scores so their mean is 50 and one standard deviation is 10. So the equation is:

$$x^{'}=50 + \frac{10(x - mean_{x})}{SD_{x}}$$

To give a silly example, if the raw data are 1, 2, 3, 4 and 5 then they have mean of 3 and SD of 1.581139. The t-score transformation converts these data to 55, 60, 65, 70 and 75 which have mean 50 and SD 10.

As ever with these transformations/standardisations, that's using the mean and SD from the data, usually the transformation would use some referential mean and SD.

Apparently this scoring/transformation is used quite a lot in Japanese education.

#### Try also

[Mean (arithmetic mean/average)](https://www.psyctc.org/psyctc/glossary2/mean-arithmetic-mean-average/)
[Standard deviation (SD)](https://www.psyctc.org/psyctc/glossary2/standard-deviation-sd/)
[Standardisation/normalisation](https://www.psyctc.org/psyctc/glossary2/standardising-normalising/)
[Transforming/transformation](https://www.psyctc.org/psyctc/glossary2/transforming-data-variables/)
[z-scores/z-transforming](https://www.psyctc.org/psyctc/glossary2/z-scores-z-transforming/)

#### Chapters

Not in the OMbook!

#### Online resources

None currently.

#### Dates

First created 2.iv.24, tweaks 3.iv.24.