8. GIS user interface standards  
  
The status of GIS specific user interface standards is explained and the existing standards and regulations for human computer interfaces with its relevance for GIS user interfaces are described.   
    
GIS, like information systems of all types, falls under the umbrella of general IS standards regarding health and safety of the user, such as the European Directive 90/270/EEC and ISO 9241, a multipart standard on ergonomics for the office environment. While these may be somewhat relevant to user comfort in the workplace, there currently are no de jure interface standards which specifically address the use of GIS. On the side of commercial standards, however, the organisation Open GIS Consortium-OGC ("The Open GIS Guide", see references) is gaining considerable momentum and support among GIS developers and is progressing on internal communication and data model standards. So far UI issues are not at the forefront of this initiative.   
  

8.1 The wider view of GI standards  
  
In the last few years a wide debate has begun among the European Geographical Information Community. Various initiatives in process are illustrated.   
  

8.2 Specific standardisation activities  
  
The GI sector is currently heavily working on standardisation. The three dimensions of interoperability (data, system, organisational) are attacked from different perspectives by different actors on several continents.   
This standardisation process is done national (by the standardisation bodies), regional (in Europe by CEN) and global (by ISO) level. Two categories of standards are produced : de jure standards (CEN, ISO), de facto standards ( in general Industry; an example in GIS domain is the Open GIS Consortium).   
   

8.3 Minimum health and safety requirements for work with GIS  
  
Poorly designed GIS user interfaces may cause problems and difficulties for the user.   
The objective of the Directive of the European Commission 90/270/EEC on minimum health and safety requirements for work with display screen equipment is to prevent that health hazards are generated for workers and employees through the use of display screen units.    
References about the implementation of this directive in various ways in the member states can be found at:   
        http://europa.eu.int/comm/sg/scadplus/leg/en/chm/c90_270.htm   
as legislation relating to safety at work and accident prevention.    
The main mechanism for testing the compliance of GIS with the European Directive is the obligation of the employer to check and analyse that workplaces are not in conflict with the requirements of the European Directive.    
 

8.4 Checklist for testing conformance with minimum requirements  
  
The checklist tests the fulfilment of the seven ergonomic principles of dialogue design:   

Î Suitability for the task. A dialogue is suitable for the tasks a user intends to perform with a GIS, if it supports the efficient and effective task execution without imposing additional workload caused by GIS features on the user.   
   
Î Self-descriptiveness. A dialogue is self-descriptive to the extent that each dialogue step is immediately comprehensible through system feedback or is explained to the user on his/her requesting the relevant information.      
Self-descriptiviness of a dialogue refers to the transparency of the application to the user, existing help and support functions.   
   
Î Controllability. A dialogue is controllable to the extent, that the user is able to maintain direction over the whole course of the interaction (i.e. speed, dialogue sequence, and amount of input/output) until the goal has been met.   
   
Î Conformity with user expectations. A dialogue conforms with user expectations to the extent, that it corresponds to the userâs model of the GIS application, his task knowledge, education, experience, and to commonly accepted conventions.   
   
Î Error tolerance. A dialogue is error tolerant to the extent, if despite evident errors in input, the intended result may be achieved with either no or minimal corrective action having to be taken.   
   
Î Suitability for individualisation. A dialogue is suitable for individualisation to the extent, that the dialogue system is constructed to allow for modification to the userâs individual needs and skills for a given task.   
   
Î Suitability for learning. A dialogue is suitable for learning to the extent, that it provides means, guidance, and simulation to the user during the learning phases.