Metadata is an essential concept to understand for functioning effectively in today’s digitalized world. But based on my interactions with students and other people who aren’t information professionals, I believe not many people know what metadata is or why it matters — even though they use it almost every day.
Alas, the inevitable popularization of the Greek prefix meta- in the wake of Facebook’s name change is likely to blur the already fuzzy (mis)understanding of the term, along the lines of what happened to cybernetics after the prefix cyber- became popular. So, it’s an excellent time to review the concept of metadata.
You’ll often hear metadata defined as “data about data,” which sounds like a Zen riddle. But it’s not hard to understand: at the core of this definition is a simple — yet fundamental — distinction between the data we care about when interacting in a specific context (what I’ll call “core” data) and data that describes that core data.
For example, when you’re looking at a photograph, the particular sequence of pixels that renders that image on your screen is the data you care about. In your phone’s photos app, you’ll see that specific sequence of pixels (i.e., that particular photo) among many other sequences of pixels (i.e., other photos.) Those images are data objects you care about when interacting in the context of the photos app. They’re why you opened the app in the first place.
But the pixels are not the only data that matters in a photos app; some data describe each photograph in various ways. For example, many pictures have a timestamp that represents the date and time when the photo was taken. This is essential information about the photo, but you don’t necessarily want to see it as part of the sequence of pixels that renders the image.1
While the timestamp is not an integral part of the image itself, it adds crucial context. Knowing the date and time when a picture was taken may allow you to recall the occasion captured in the image or determine that this is your last photo of a late cherished friend.
Timestamps also allow you to organize and navigate your photo collection. You’ll find old photos more quickly if you know when they were taken. If the photos app didn’t have access to metadata about each photograph, you’d have to look at them one by one if you wanted to locate a particular image.
So, timestamps are very useful. But they’re not the only metadata that describes photographs. Depending on your camera and photos app, you may also be able to locate your pictures on a map of the world via geotags — i.e., data about where in the world the photos were taken. Again, the location data isn’t part of the sequence of pixels (i.e., the core data) that render the picture; instead, it describes that core data. Hence, metadata.
Metadata is fundamental to information systems. And because so much of today’s world runs atop information systems, we encounter it all the time. Often it’s hidden from us, as in the photos app when we’re looking at pictures. But sometimes, we can see metadata elements presented alongside the core data.
For example, this blog post’s core data is the text you’re reading now. But there is also metadata associated with this post, including a timestamp and tags. You can see both in the header of the page, underneath the post’s title. There are also other metadata associated with this post that you can’t see unless you examine its source code. This metadata serves organizational purposes, such as grouping posts based on shared topics or allowing search engines to index the site’s content properly.
Most of the time, we’re more interested in core data than metadata. And since much metadata is hidden in the background, we don’t often think about it. But it’s important to know what metadata is, how it works, and how we can use it to our advantage. Most of the digital systems and tools we interact with use metadata extensively, and many apps allow us to set it ourselves. Learning how to do so can significantly amplify our thinking, aid our memory, and simplify our workflows. So, it behooves us to “go meta” — before the term gets watered down.
A photo’s timestamp is such important information that some pre-digital cameras would burn an ugly timestamp onto the photograph itself, making it a part of the image’s core data. ↩