4. ANALYSIS OF GIS USERS, TASKS AND WORKFLOWS  
  
Objective of the "Analysis of GIS Users, Tasks and Workflows" section is to present the outcomes of an experiment of using Human-Computer Interaction (HCI) approaches for characterizing users, tasks and workflows for the GIS domain.   

      
    The objective is finding out what users think and feel about the use of a GIS system.  

Successful GIS applications depend heavily on how well final usersâ needs, attitudes and requirements are identified.   
Obviously, GIS cannot be tailored to individual differences. However, the identification of specific GIS user groups and usage scenarios - representing users with similar abilities and skills making similar use of the same GIS functionalities - can be of enormous help in "shaping" a GIS.   
GIS user groups and typical usage scenarios can be described by using a number of techniques developed within the Human-Computer Interaction discipline, such as structured interviews, questionnaires, direct observation and many other.   
        
Such techniques grant systems developers and customizers the possibility of characterizing GIS user groups by analyzing:   

• who the end-users are,
• which tasks they perform with GIS in order to achieve specified goals,
• when and where they use GIS,
• the way they react and what they expect from the usage of GIS.

Two of such GIS users characterization methods - a structured interview supported by a written questionnaire and a GIS usability  checklist - have been employed in the "Guidelines" on a sample of some thirty subjects from Italy, Greece, Portugal, Spain, Germany and the Netherlands.   

A first result of the interviews has been that of deriving a clear understanding of the different typologies of users  and stakeholders acting in the GIS scenario:   
  

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    Users opinions and requirements with respect to the GIS user interface

Particularly interesting results regard the usersâ overall position when evaluating the usability aspects of the GIS user interface they normally use.   
Usability is a concept which refers to the extent to which an end-user is able to carry out tasks successfully  (effectiveness), easily (efficiency) and pleasantly (user satisfaction) using a computer system.   

The widely used usability checklist developed by Ravden and Johnson was chosen as a suitable method to collect the opinions of GIS end-users.    

The following bar chart shows the interviewed usersâ opinion on the usability aspects of the GIS user interface they use:  
  

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    Overall evaluation of GIS user interface (UI) usability aspects

                                                  

As it can be expected, users would like their GIS interface equipped with clearer informative messages and options for correcting/preventing errors (usability aspects: "Infomative feedback" and "Error prevention and correction").    
Many feel they canât control their user interface to suit their needs and requirements because of a not really flexible structure of the system (usability aspect: "Flexibility and control").   

When the 9 usability criteria above are cross-correlated to some of the most common usability problems the users encounter using GIS (e.g. working out how to use the system, having to spend a lot of time for learning the GIS functionalities), it is possible to detect critical aspects of GIS functionality which merit closer attention  (e.g. improvements) by developers and customizers, as well as to reveal aspects of GIS usage which satisfy the users.   
  

TYPICAL SCENARIOS OF GIS USE  
  
A typical GIS usage scenario illustrates a GIS project with its GIS users, the tasks they perform, how users interact with each other and with other stakeholders. A typical scenario of GIS use has two important objectives:    

• to help developers and customizers to find out what kind of GIS user interface is needed for the different levels (e.g. beginner, frequent, expert) of usage and   
• to help the users to describe their requirements.

     A properly constructed GIS usage scenario has at least three components:   

•  Task breakdown, a diagram showing all the steps in any generic GIS activity;
•  Workflow, to recognize relationships and dependencies among people directly and indirectly involved in GIS work;   
•  User requirement, identified for performing the given task in order to achieve the goal.

From the analysis of typical GIS scenarios, one can find out that focusing attention on user tasks and how tasks break down into sub-tasks helps developers to design GIS systems which more accurately reflect what the user actually  wants to do.