Data about data. It’s what lets you search ten thousand photos in a second — and it’s why a message log with no messages in it can still tell a stranger a lot about your week.
No reading — this page is the reading. Runestone doesn’t have a metadata section, so everything you need is here.
Big Data. Yesterday a dataset had records and fields. Today, a second layer: the data that describes the data. Plant this one deep — it comes back in Unit 7 (security) and Unit 8 (impact).
Metadata is data about data. The photo is the data; the camera, the timestamp, and the GPS coordinates are metadata. A song’s audio is data; its length, artist, and date-added are metadata.
| The data | Its metadata |
|---|---|
| A photo | date & time, camera model, GPS location, image size |
| A text message | sender, recipient, time sent, time read |
| A document | author, created date, last edited by, file size |
| A web page visit | your IP address, device, browser, time, the page you came from |
Metadata is useful. It’s how you search, sort, and organize data without opening every file. Changing metadata (renaming a file, adding a tag) doesn’t change the data itself.
This is one week of Sam’s call log. There is no content — only metadata. Answer each question from the log, then reveal.
Five questions. Ask: is this the thing, or a description of the thing?
That sentence can be completely true and still leave a great deal exposed. When a company says the content is private, the next question is always: what about the metadata? Who you contact, when, from where, and how often is collected far more widely — and you just saw what a single week of it gives away.