Comparison of datasets

Freedom of information request reference no: 01.FOI.23.029972

I note you seek access to the following information:

I am writing in regards of a comparison of datasets I did with the open data download from police.uk and the crime data excel file Metropolitan Police sent me. I noticed there are more LSOA codes in police.uk records compared to the file Metropolitan sent for the years of 2020-2022.

I am seeking information that may lead to understanding why there are more LSOAs from the police.uk source compared to Metropolitan data source.

Are there different LSOA boundaries/geographies used from each data source?

One crime category that had a big difference in counts was 'violence and sexual offenses'; is there underreporting from either source.

Any information you can provide will be appreciated.

Decision

I have today decided to disclose the located information to you in full.

Please find below information pursuant to your request above.

Every 10 years the Boundaries Commission re-evaluates the wards (and other boundaries within them) which includes council consultation.

It is believed that the most recent changes came into being in 2022. The update of multiple pieces Software or systems that uses these layers (Ward and LSOA) is a very complex and manually time consuming task. This process can take many, many months to undertake.

Not all systems will be in sync with these changes, causing difficulties. Cut off dates between one set and another is difficult to decide, which in turn cause further mapping requests. All of which is time consuming.

Additionally, date range spans both versions, therefore it is not possible to get a like for like comparison, as the number of wards (or LSOA) in one Borough (Council area) and even if the ward count is the same, the orientation and/or the names might be completely different.