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. The encryption is AES-256, which we believe has never been cracked, even when Government and Police are very keen to see what is on a suspect's computer.

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

We have mostly used postcodes 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.

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

"I really think that the HRBQ is a wonderful piece of work in terms of getting useful information for so many different organisations in one go." Healthy Children's Research and Statistics Officer

Research and Statistics Officer

"...the most comprehensive health education survey."

Daily Telegraph

"The data from last time were spot-on and we have done lots of work with it. We are very keen to repeat the survey." Headteacher

Headteacher

"The Health Related Behaviour Survey is an incredibly useful resource for (us) as it provides schools, with invaluable data which can inform curriculum content, methods of lesson delivery and empower schools to better meet the needs of their pupils."

Health Education Advisor

"The survey reports have been used to inform commissioning at specific commissioning groups. They are also being used within our Extended Schools Clusters and to inform The Annual Public Health and the Joint Strategic Needs Assessment." Programme Manager - Young People

"The Unit has a unique historical and contemporary archive of young people." Prof. Ted Wragg 1938-2005

Prof Ted Wragg, 1938-2005

"Our use of the Health-Related Behaviour Questionnaire was commended as part of our accreditation for the National Healthy Schools Scheme." Headteacher

"Many thanks to SHEU for your excellent professional support over the years."

PSHE teacher

"The children found the survey very interesting and enjoyed doing it." Class Teacher

Class teacher

Any comments on specific survey questions that may have caused difficulty?
All questions are clearly worded and easy to answer

Class teacher