Estimation and adjustment
Estimation and adjustment helps us estimate how many households and people are missing.
While the census aims to capture the whole of Scotland, we expect that some people and households will be missed.
We use estimation and adjustment to find out how many households and people we collected information from in the census.
If evidence suggests the census has missed some people, we add records so we have a census dataset that covers Scotland’s entire population.
Estimation
Estimation produces overall population and household estimates.
Estimation requires clean and complete datasets for both the census and the Census Coverage Survey (CCS).
We link the census and the CCS together. We then use a process called dual system estimation to give us an estimate of how many households or people the census missed.
We’ll correct our estimates to account for people who were counted more than once, or counted in the wrong place.
Adjustment
Adjustment creates new records for the people and households missed by the census. It uses completed census records as donors to create these new records.
Combined with the estimation process, adjustment gives us a census dataset for the whole population.
Creating new records
We can create new records by adding people to existing households or communal establishments.
We can create new households in a ‘space’ we already know about. This can be a known address with an occupied property from which we received no response.
We can also create new households in a ‘space’ that is not in our address register. In this case we’ll give them a real postcode so we know where they are.
Adjustment is a complex process. For each census record it calculates how likely it is that a similar person or household would be missed from the census.
We use this information to choose existing person records to use as donors. Key characteristics from these records are used to create new person records. This is the unit imputation process.
Find out more
Find out more about estimation and adjustment in PMP001: Estimation and Adjustment Methodology.