It's worth reading their entire article, but they include a summary table that lists all the types of information relevance and ones specifically applicable to mobile, geolocative functionality. Relevance, in this sense, refers to the degree to which information returned by a digital service satisfies various user needs and desires. (Read more about information relevance on Wikipedia).
In my efforts to keep updated on location based services, I've noticed that many apps focus on the relevance criterion of proximity to the neglect of all other (possibly more pertinent) factors. De Sabbata and Reichenbacher offer an invaluable list of other factors that developers should consider for more effective and engaging user experiences. Even better, their work is based on actual user studies.
Here is their table of relevance criteria, based on the classes of: properties (of the object), geography, information, and presentation (of the end result, to the user).
For details on a particular concept, the article has useful explanations.
Although location based services are, by definition, preoccupied with location (i.e. spatial proximity) this list offers guidance on other criteria to add that would greatly improve current locative apps.
This list seems definitive to me, but if anyone has a criteria to add or refine, I'd love to hear it below.