Creating data: the difference between summing and averaging
When uploading your own data there are two ways to create the data: summing or averaging.
Postcode-level data imported into Local Insight is aggregated to Output Area (OA) level and Lower Layer Super Output Area (LSOA) level - the system does not store the raw postcode data. For each OA and LSOA, a total is calculated based on the data values for the postcodes within each OA/ LSOA. So areas containing no postcode-level data will not have any calculated data.
When setting-up the dataset you are given the option of whether you would like the data to be ‘summed’ or ‘averaged’:
Summed data is simply added together to produce a total. For example, this would be appropriate if you were interested in “The number of people in my survey who used the service”
Averaged data is averaged across the postcode-level data in the area. For example, this would be appropriate if you were interested in “The proportion of people in my survey who were happy with the service”. (Where the value of 0 equals unhappy and the value of 100 equals happy)
Remember:
Data for each of the custom areas is created by summing up the postcodes within the OAs and LSOAs used to define the custom area. As with standard areas, suppression will be applied if a custom area has fewer than the suppression-threshold number of cases. As the original uploaded data is not stored in Local Insight, custom areas that are created after a dataset has been uploaded will not show data for that dataset.
If suppression has been applied, then areas with fewer than the suppression-threshold number of cases will not save any data values, and will instead show the average for the data upload. For a more detailed explanation of data suppression see this article.
