100 Personal Content Experience: Managing Digital Life in the Mobile Age content created with other iLife suite applications (photos, videos, songs) is all easily accessible in the Garageband browser for incorpora- tion into the podcast under editing. Here, Apple has raised the abstrac- tion level from fi le management into content management. The metadata that the iLife suite uses is not directly visible, as it is used by the applications, not the users. This software suite was written by a single manufacturer, so the metadata formats were easier to agree upon. In cases where multiple companies are involved, agreements on the formats can become excruciatingly diffi cult. 4.6 Existing Approaches In the following we review some of the existing metadata standards. We have chosen these, either because they are popular with consumer devices or because they illustrate technical aspects relevant to our purpose. Many other formats exist, so this treatment should not be considered as an exhaustive list. For a review on additional current metadata standards, refer to Smith and Schirling (2006). COMMENT: MOBILE MEDIA AND METADATA The increasing number of media creation devices is adding to the organization and media management problem for per- sonal media. Content describing metadata is seen as the most prominent answer to this problem. However, the current media content metadata standards, such as EXIF, Dublin Core, MPEG-7, and IPTC, have shortcomings when it comes to the domain of personal media. This is because the standards were designed for public and professional uses of media (e.g., public archives, commercial uses, professional media creation). They were not designed with personal media or user-generated media in mind. In personal media some fundamental principles about public and professional media and metadata do not hold true: Personal media and metadata are mostly private, not public. They are highly semantic, because the meanings associated to them are personal, and this means that automatic metadata generation is more diffi cult. Personal uses are different from public uses, for example, personal media is often shared in a private context within a social network. Lastly, metadata is a non-trivial concept for the average consumer to learn. None of the currently used media content metadata standards were designed with these principles in mind.