Some embodiments of the invention provide novel methods for editing the value of an attribute of a media item (e.g., a media content or a media operation) for a media editing application. Such attributes of a media item can include scale, rotation, opacity, pan, volume, etc. In some embodiments, a media editing application represents the changing value of such an attribute over a duration (e.g., a duration of time, a duration of frequencies, etc.) as a key-indexed geometry. A user of the media editing application can manipulate these geometries to change the attribute value over a duration. Such geometries may include graphs and shapes. For such applications, some embodiments provide novel compressed geometric representations (i.e., collapsed views) of one or more uncompressed key-indexed geometries (e.g., graphs or shapes). Additionally, other embodiments provide a novel method for editing the value of one or more attribute directly in a preview display area used to view the composite presentation created in the media editing application.