Parent/carer email about postcodes

What precautions do you take to make sure an individual cannot be identified from their postcode?

There are general precautions about the security of our servers which I am sure every good business would adopt, but we make a special effort with postcodes.

I don't know if your child competed the survey online or on paper - the account to be given in each case is slightly different.

Online, the postcodes are encrypted using GnuPG when storing, and downloaded with the encryption intact (screenshot). 

Screenshot 2014-07-30 16.28.29.png

They are decrypted only when the postcode information is required; the decrypted postcode is not stored but discarded once the analysis is complete.

For paper surveys, we store only part of the postcode with the case, replacing the last two letters with "99", like this:

SCHID PUPILID SEX AGE YEAR PCODE Q1 Q2 etc
712 1 0 12 8 9999999 1 0
712 2 0 13 8 SG19399 0 1
712 3 1 13 8 SG19299 0 1
712 4 0 13 8 SG19399 0 0
712 5 0 13 8 SG19399 1 0
etc       

We store the whole postcodes separately from the rest of a pupil's answers as below, tagged with two numbers which together can identify an individual case, and merge the information only when necessary, and don't keep the merged data file.

SCHID PUPILID PCODE1 PCODE2
746 2 CB013 LN
746 3 CB013 LN
746 4 CB013 BN
746 5 CB014 ET
746 6 CB013 PU

In Cambridgeshire, we have used postcodes only for things like allocating pupils to districts - as a pupil may go to school in one district but live in another.  The reports produced are at the level of district rather than at the pupil level.

20% Cambridge City
16% East Cambs
22% Fenland
19% Huntingdonshire
19% South Cambs

Elsewhere, we have used postcodes for allocating deprivation scores, assigning ward-level information, and so on; again, we keep the derived information and discard the postcode. An example of an analysis using deprivation scores is given below:

Topics: 

Comments about SHEU

"Over the last twenty years you have achieved much. The surveys and subsequent reports have painted the clearest picture we have of what young people are doing and what they think." Tribute from OFSTED to John Balding, presented at his retirement lunch, May 2005

OFSTED

"We're very happy to commission another survey from you. Our colleagues in School Improvement are dead keen to work with us on this. During our last LA Inspection, we were flagged from our Tellus data as having a bullying problem. We could demonstrate with our SHEU data - which had a much better sample size and coverage of the authority - that we did not have the problem they suggested. The Inspectors went away happy and we are definitely surveying again with SHEU."

Local Authority Senior Adviser

Any comments on specific survey questions that may have caused difficulty? No problems. My children were fully briefed before the survey and they understood that they could miss questions if they did not want to answer them. We did not have any children with any concerns regarding the survey at all.

Any comments on the use of the web site? No it was easy to use.

Any general comments on the exercise? The children really enjoyed completing the survey, It has lead to many positive discussions about our health and how we all have slightly different experiences and home lives.

Class teacher

"Thanks for presenting the survey to local schools this morning, I just wanted to thank you for such interesting and thought-provoking information.  
I’m really glad we were able to take part - the information (particularly headline data and differences) will support us to have some really interesting questions with the Year group as a whole about the sense they’re making of this; what they think it might mean in terms of changes they might make, and what they need to support them in this."

Deputy Headteacher

"The system works and I find quite a lot of it useful in my work. I've also recommended it to others."

Teenage Pregnancy Manager

Any comments on specific survey questions that may have caused difficulty?
Pupils at our primary school found the questionnaire very easy to understand and most of them completed the questions in less than 45min.

Teacher

"You and the team have the evidence to show how young people's behaviour has or hasn't changed over time." 
Tribute from a Health Education Co-ordinator to John Balding, presented at his retirement lunch, May 2005

Health Education Co-ordinator

"I have valued greatly the work I have done with the team in Exeter, it has been a highlight of my years here." Health Promotion Specialist

Health Promotion Specialist

Please could our College be part of the SHEU survey this academic year? We did it in 2016 and 2017 and found it incredibly informative and it helped us shape our PSHE provision.

Assistant Principal

"Please send an additional copy of our report - it is the most requested and borrowed item in the whole library." Health Promotion Unit

Health Promotion Unit