The Different Kinds of Metadata or File Properties

In addition to the actual content of a file, there is information about the file itself. This type of information is sometimes called metadata. This is data about the data in the file. (Meta comes from Greek and has the sense of beyond.) By default, most files possess the basic properties Name, Size, Type, Date Modified, and Attributes. In addition, the Details view of Windows Explorer allows for the display of 28 others. (If you install Adobe Acrobat Reader, you will have “Keywords” added as well.) The figure on the left shows the list of possible file properties that can be displayed in Windows Explorer. The four standard default properties are checked. Many of the listed properties are specialized and apply only to certain file types. In particular, multimedia and image files may have a variety of metadata. Microsoft Office documents also can contain considerable information in addition to their usual contents.

Microsoft DOC files, JPEG image files, and WMV, WMA, MP3 multimedia are some of the file formats that allow for metadata in addition to the standard properties. Metadata may be added to the file properties when the file is created or or it may be inserted later. For example, some cameras may automatically add image data for categories such as the dimensions, date taken, and even camera model. More discussion on images is given by Ed Bott. Music files may have data for properties such as artist, track number, or album title.

Microsoft Office files can have metadata in addition to the file properties considered here and the subject of all of the possibilities is beyond our scope. For further discussion of Office files, see this article.

Using Metadata to Organize Files

If Windows Explorer is opened in the Details View, the various types of file properties can be used to sort and organize your data. The details of how to add properties to the Details view of Windows Explorer and how to use the "Show in Groups" function is discussed on another page. An example of sorting a file list is given in the figure on the right. In this case, the file property "Type" has been used as a criterion for sorting the files. Other properties could be used as a way to group files as well. For example, a collection of music files could be grouped by "Artist" or a collection of videos could be sorted by "Genre".

A very flexible category of metadata is the property "Comments". A number of file types allow the user to enter personal data in this category. This can be a very flexible method that allows the sorting of files according to individual schemes devised by the user. In the next section, we look at how to add information to the properties of a file.

Adding or Modifying Metadata

The properties sheet of file types that can have some of the additional types of metadata can be used to enter new information. To open the properties sheet of a file, right-click on it and choose "Properties' from the context menu. If the properties sheet contains a tab "Summary", clicking on it will open a dialog box where information can be entered. Not all file types will have this feature and the entries that are available will depend on the file type. There are also two buttons on the "Summary" tab window. They are "Simple" and "Advanced" and they present the metadata in different ways. The figures below show the two dialog boxes for a JPG file. The "Simple" view has some text boxes for making entries for certain of the properties. In some file types some of the text boxes will be grayed out. For example In the figure below, the property "Category" cannot be edited. The "Advanced" view lists more properties than the "Simple", also including some that cannot be edited. These are properties such as size and are listed in the top section of the dialog box. Editable properties are in the bottom section. Data can be entered by clicking in the blank area to the right of the name of the property. A text box will then appear where data can be placed.

Dialog boxes for two views of "Summary" in properties sheet for JPG file

Simple view	Advanced view