SDMT standardised scores

Discussion in 'Special educational needs' started by MrsY, Feb 11, 2015.

1. MrsY

Does anyone know how to calculate standardised scores for the SDMT? Although there's no conversion table, I understand that they can be calculated from the manual - but it's not clear how.

2. camptownracesNew commenter

You calculate the standard scores in the normal way - using the mean score and the standard deviation quoted in the manual for your age group and situation, plus the raw score you have recorded for the subject. You calculate how many standard deviations your raw score is from the mean, multiply by 15 then add or subtract from 100.

Not all the tables in the manual give enough detail for you to do this, but I think they do cover ages 11-18, male and female: don't think there's a combined boy/girl table.

3. moonpennyOccasional commenter

There is a page of means for adults in the manual too so using the above formual it is pretty easy to do.

There was a list distributed a few years ago widely used which was incorrect.

4. tpfrobson0

I know this is rather out of date, but in case it's any help to anyone, I've just put my computerised calculator online, which might simplify the conversion of raw scores into standardised scores: http://edtestcalculator.weebly.com/

Flanks and moonpenny like this.
5. moonpennyOccasional commenter

Thank you!

SASC recently updated their guidance re: SDMT including calculating a score which falls between a range, rather than a single score.

However, Patoss have advised that the forumla they have given out to work out the SS can still be used as long as this formula is stated in the report.

BTW: did you devise the calculator yourself? Looks very useful.

6. FlanksSenior commenter

Hi Tpf

Quick thank you for also making this calculator. I know that the spreadsheet which is very widely used to score SDMT is incorrect and so I created my own spreadsheet a while ago.

Today I scored a young lady to a shockingly low score which panicked me about whether my own maths was correct. Your calculator reassured me that I had calculated correctly!

Rather worryingly, the widely used spreadsheet would have scored her nearly 10points higher, which is hugely worrying! I wonder how many assessors are mis-scoring this test because they are not reading the SASC guidance and/or lack the confidence to use the manual to generate scores themselves?

8. lmason24

Is there any chart about what the standardized score correlates too? I have a raw score, calculated the standardized score, but honestly based on the manual, I have no idea what it actually means.
8 year old girl. Raw score 18/20, standardized score 85. I'm assuming this puts her in the average range?

9. FlanksSenior commenter

If you don't know what a score of 85 means then why are you using the test???

10. choli2New commenter

Hi Guys,
I have to demonstrate (CPT3 certification) that I can correlate my raw score to a standarised score. I have used the Dyslexia Portfolio assessment and although it is great that it generates an online report I need to show that I can actually do it myself?Therefore, I would need the normative table. Would you know how can I get hold of one? I have looked in the manual and unfortunately it's not in there. Any suggestions?
Thanks

11. FlanksSenior commenter

Do you mean you need to show the ability to calculate a standardised score?

If so, the process is fairly simple, but you will need to get some data out of the manual.

Standard Score = (raw score - mean score) / Standard Deviation

All credible tests report mean scores (often by age group) and standard deviation (again, by age group) in their manuals.