1.2.1. User Actions

User Actions and Questions

Using LBS involves a set of different basic actions. Five elementary mobile actions with a reference to geo-information are given above: locating, navigating, searching, identifying, and checking (Reichenbacher 2004). Checking uses not only geo-information but involves also time, since it refers to state of entities or events as well.

An activity is a sequence of actions conducted by a human being aimed at achieving a certain objective (Nardi 1996). This objective could be solving a problem or a task. In mobile situations objectives are for example orientation, finding persons or finding the way to an object. The objectives can also be expressed by questions which the user of LBS wants to have answered. The following table relates the elementary mobile actions with the questions they try to answer and further to basic geospatial operations that are used.

!	action	questions	operations
	orientation & localisation locating	where am I? where is {person|object}?	positioning, geocoding, geodecoding
	navigation navigating through space, planning a route	how do I get to {place name|address| xy}?	positioning, geocoding, geodecoding routing
	search searching for people and objects	where is the {nearest|most relevant| &}{person| object}?	positioning, geocoding, calculating distance and area, finding relationships
	identification identifying and recognising persons or objects	{what| who| how much} is {here|there}?	directory, selection, thematic/ spatial, search
	event check checking for events; determining the state of objects	what happens {here|there}?

Information for searching, identifying and checking

The two basic actions locating and navigating mainly rely on geospatial information. Searching, identifying and checking however need a bigger variety of different information. Additionally to the geospatial information also other types of information are needed:

• Comprehensive static information are mainly contents such as a yellow pages. Such information stays constant over a while and could of course also be retrieved via other media (book, newspaper, map, TV, internet, etc.)
• Topical information is information that may change while the user is on the move. In such a case the information checked previously from other media may no longer be valid. Examples of such topical information are traffic information, weather forecasts, last-minute theatre ticket deals, or on-line chat.
  In addition to topical information, the users will need guidance on how to proceed in the changed situation. For instance, a train schedule as such can be obtained elsewhere but once on the move, the user will need information on delays and estimated arrival times.
• Additionally safety information has key importance, e.g. actual information on the state of the roads or hiking trials, weather changes, danger of falling rocks, etc. Car drivers or boaters also need information in emergency situations, e.g. roadside help in a situation when the car breaks down
• Far too often users are seen as passive information consumers. However, letting the users participate and provide their opinions and recommendations could enhance many services with personal information. An example therefore would be notes on good places to go on mushroom foray

In general users wish to maintain control over information content, delivery (pull/push, text/picture/video) and personal privacy and security. Security issues are shortly discussed in the subsection on context.