Data, information management and digital media
What this domain covers
This domain is about turning raw data into useful information and managing it responsibly. Candidates should understand the data-information-knowledge distinction, data types (text, numeric, dates, images, audio, video), validation and verification, and the difference between them: validation checks whether data is reasonable (range, type, format, presence), while verification checks whether it matches the source (double entry, visual check). Know how databases are structured (tables, records, fields, primary and foreign keys, relationships) and how queries and reports support decisions.
Concepts to know
- Data quality: accuracy, completeness, timeliness, relevance, consistency.
- Backup and recovery: full, incremental, differential; the 3-2-1 rule; restore testing; retention schedules.
- Privacy and records: collecting only necessary data, access controls, consent, retention and disposal.
- Digital media: file formats and compression (lossy versus lossless), resolution, bit depth, frame rate, codecs, colour models, metadata and accessibility (captions, alt text).
- Presentation: choosing format for purpose, such as JPEG for photos, PNG for transparency, MP4 for video distribution.
Traps
A classic trap is confusing validation with verification. Another is assuming a backup is reliable without a tested restore. Questions on compression often test that lossy compression discards data permanently while lossless preserves it. Also watch for over-collection of personal data and for assuming metadata is invisible or harmless; it can reveal sensitive information.
Worked example / rule of thumb
Rule of thumb: validate on entry, verify against source, back up and test. For a form accepting a date of birth, a range check (not in the future, not implausibly old) is validation; asking the user to re-enter it is verification. For a media task, choose the format from the delivery purpose and the acceptable quality loss.
Study tip
For each data-quality attribute, write one failure example and its consequence. This makes scenario answers concrete.