Chapter 3. Using Metadata - Technical Metadata

The most basic technical metadata items are collectively known as "data attributes," which are technical specifications and parameters that inform how a piece of data is designed within a technical system. Data attributes include a data element's field length (e.g., up to 12 characters), element type (alphanumeric, date, etc.), permitted values (such as, 0-999 inclusive), code sets (e.g., M = male and F = female), and technical translations (e.g., changing date data from a DDMMYY to a MMDDYYYY format). More information about data attributes commonly used in the field of education can be found in the NCES Handbooks Online.

Storage location identifies the physical and/or electronic location where data are stored. This includes a building site, such as "in office #213" or "at the offsite storage facility at 123 Jones Street"; the machine, such as "computer/server serial number 123"; and the database, table, and column, such as, "staff_db, assignment_tbl." Because data do not just appear in a data system and stay there indefinitely, other useful sets of technical metadata are data source and data target. Data source refers to information that identifies where data came from—either technically (e.g., a particular database) or operationally (e.g., a particular survey). Data target, on the other hand, is a description of the data’s predicted destination, such as another database or a report. These metadata are critical when programmers are designing extract, transform, and load (ETL) processes that move data from one system to another.

For some types of datasets and processes, load time can be important metadata. When processing capabilities are strong or data loads are simple and range from milliseconds to one or two seconds, load time may not be worth measuring. But a school district that loads 200,000 attendance records each morning needs to know when the system is going to be engaged at full capacity for a couple of hours.