How do direct census data differ from derived census data?

In the context of demography and census procedures, the distinction between direct and derived data is based on how the information is obtained and processed.1

Direct Census Data

Direct data consists of the specific answers provided by respondents to the questions included on a census schedule. This information is categorized into two primary types:1
* Administrative items: Details such as names and addresses used primarily to manage and guide the enumeration process itself.1
* Compilation items: Specific demographic or social facts—such as birthplace, marital status, occupation, or citizenship—that are used directly to compile census tables.1

Derived Census Data

Derived data is not collected through a single direct question. Instead, it is generated by classifying, interrelating, and analyzing the answers to various direct questions. Examples of derived information include:1
* Total population counts.1
* Urban-rural distribution.1
* Household or family composition.1

Essentially, while direct data provides the raw building blocks, derived data offers broader insights and statistical summaries that emerge from processing those individual responses.1