Page 6: Metadata

Unit 5, Lab 3, Page 6

On this page, you will learn about metadata (data about data) and how they can be used.

DAT-2.B.1

Metadata are data about data. For example, the piece of data may be an image, while the metadata may include the date of creation or the file size of the image.

DAT-2.B.2, DAT-2.B.3, DAT-2.B.4, DAT-2.B.5

Data can even include data about itself. For example, a music file might contain data describing the song title, artist, album, genre, record label, etc. Or an image file might include data for the date that the picture was taken, the location where it was taken, information about the camera settings, the serial number of the specific camera, etc. This kind of information about data is called metadata. Metadata tell you additional information about the data you are working with and can be used to organize and manage your data. For example, you can use metadata to find all of your photos from a particular time and place or to restrict access to all videos recorded by your old phone. Metadata are connected to but different from your data and can be changed without impacting the primary data. For example, changing the album name of a song won’t change what the song sounds like.

Because metadata are often not displayed by software, it’s easy to violate privacy without realizing it when posting data online…

“…an electronic camera is not just a camera. Harry Potter and the Deathly Hallows is, as far as anyone knows, the last book in the Harry Potter series. Its arrival was eagerly awaited, with lines of anxious Harry fans stretching around the block at bookstores everywhere. One fan got a prerelease copy, painstakingly photographed every page, and posted the entire book online before the official release. A labor of love, no doubt, but a blatant copyright violation as well. He doubtless figured he was just posting the pixels, which could not be traced back to him. If that was his presumption, he was wrong. His digital fingerprints were all over the images. (Blown to Bits, page 24, emphasis added)

Brian, you want to make the point that privacy of metadata is important. –MF, 6/6/20

    DAT-2.B

  1. These questions about metadata are similar to those you will see on the AP CSP exam.

    A new mobile phone company—unbeknownst to its customers—periodically records random snippets of their conversations and considers the recordings as data. In addition, it collects the following metadata on the conversations:

    • The start and end time of the conversation
    • The phone numbers of the users in the conversation
    • The GPS locations of the users in the conversation

    For which of the following goals would it be more useful to analyze the data instead of the metadata?

    To determine if any of its users was present at the time and place of a crime.

    To determine the time of day the app is used most frequently in a certain geographic location.

    To determine the language most commonly used in user conversations.

    To determine the most active users of the app for a given year.

    Which of the following is not an example of metadata?

    Data about a digital image describing the size of the image, image resolution, color depth, and when the image was created.

    Data about a text document containing information about the length of the document, its author, the date the document was written, and a short summary of the content.

    Data about a pack of wolves describing their habitat, hunting habits, diet, and sleep cycles.

    Data about a web page containing a description of page content and a list of key words linked to the content.