Decision Support System Course
Dr. Aref Rashad
Part:3
User Interface
February 2013
Decision Support Systems Course .. Dr. Aref Rashad
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Mechanisms of User Interfaces
User Interface Components
• Action Language
• Display or Presentation Language
• Knowledge Base
February 2013
Decision Support Systems Course .. Dr. Aref Rashad
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User Interface Requirements
• Allow users to work in a comfortable way and to focus on the data and
the models in a way that supports a decision.
• Must be easily learned, simple, structured, and consistent so that users
know what to expect and where to expect it on the screen
Less is more.
• Enable users to direct, don't force them to discuss.
• Design for the probably; provide for the possible.
• Keep tools close at hand.
• Provide feedback.
• Provide for direct manipulation and graphical input.
• Avoid unnecessary reporting.
• Satisfy the user's perceptions, feelings and opinions about the decision
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Decision Support Systems Course .. Dr. Aref Rashad
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The purpose of the user interface is communication between the human and the
computer, known as human-computer interaction (HCI), the goal of HCI is to
minimize the amount of incorrectly perceived information (on both parts) while
also minimizing the amount of effort expended by the decision maker.
Goals of the User Interface
• Reasonable speed at which decision makers can glean available
information
• Good Presentation of data, important and informative patterns are
highlighted, consider attraction attributes like include the hue and
intensity of the color, the location, the orientation, the form of the object
(width, size, shape, etc.), and motion.
• Provide choices.
• Optimize for responsiveness; accommodate latency.
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Decision Support Systems Course .. Dr. Aref Rashad
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Mechanics of User Interface
Range of mechanisms for user interfaces:
• Exist today
•Coming in the near future
keyboard and the mouse
Mobile phone
pen-and-gesture-based device
large screens
virtual reality
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Decision Support Systems Course .. Dr. Aref Rashad
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Pen-Based System
Mobile Phones as Input and Output Devices
Wall Screens as Displays
Virtual Reality Devices
User Interfaces Components
User Interface Components
• Action language
• Display or presentation language
• Knowledge base
Modes of Communication
• Mental Model
• Metaphors and Idioms
• Navigation of the model
• Look
Basic Action Language Types
The action language identifies the form of input used by
decision makers to enter requests into the DSS
Five main types of action languages have been used:
•
•
•
•
•
Menu format
Question-answer format
Command language format
Input/output structured format
Free form natural language format
Menu format
The most common action language today
Display one or more lists of alternatives, commands, or results from
which decision makers can select.
Provides a structured progression through the options available in a
program to accomplish a specific task.
Use the process of guiding the user through the steps with a set of
pictures or commands that are easy for the user to understand
Appealing to inexperienced users, who can thereby use the system
immediately
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Decision Support Systems Course .. Dr. Aref Rashad
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One Form of a Menu
A “Ribbon Bar” as a Menu
Menu Design Considerations
Menu choices should be clearly stated. The names of the
options or the data should coincide with those used by the
decision makers
Options to be listed in a logical sequence
Group commands and objects together, and allow users to
select all attributes that are appropriate.
Apply nested menu, if needed
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Decision Support Systems Course .. Dr. Aref Rashad
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Independent Command and Object Menus
Combined Command and Object Menu
Nested Menu Structure
Question-Answer Format
A second option for the action language is to provide users
questions they must answer.
One attribute of the question-answer format in some
environments is the opportunity to embed information into
the questions
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Decision Support Systems Course .. Dr. Aref Rashad
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Question-Answer Format
Personalized Question-Answer Format
Command Language
The command language format allows user-constructed
statements to be selected from a predefined set of verbs or
noun-verb pairings
The command language format allows the user to control
the systems' operations directly providing greater latitude
in choosing the order of the commands
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Decision Support Systems Course .. Dr. Aref Rashad
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Command Language Format
Input-Output Structured Formats.
Present users with displays resembling a series of forms, with certain
areas already completed.
Users can move through the form and add, change, or delete prespecified
information as if completing the form by hand
Since the completion of the form is integrated with the development of
the design, as design features change, the form will be updated
immediately.
Free-Form Natural Language.
No preconceived structure in the way commands should be entered
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Decision Support Systems Course .. Dr. Aref Rashad
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I/O Structured Format
Free-Form Natural Language Format
Display or Presentation Language
Describes how the computer provides information back to the user.
Visual Design Issues
The goal of the display of a DSS is for people to be able to understand and
appreciate the information provided to them. The display should help
users evaluate alternatives and make an informed decision and do that
with a minimum amount of work
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Decision Support Systems Course .. Dr. Aref Rashad
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Rules of Visual Design
The first rule of design is that the display should be readable
Fewest possible words, User Terminology, Readable font
The second rule of design is to control color
Neutral color, enough contrast, highlighting
The third rule of design is to control location and size.
The largest item and the one on the topleft corner will get user’s attention
first, logical order
The fourth rule of design is to keep the display organized
Avoid noise, Consistent use of size ,shape and location
The fifth rule of design is to make the navigation easy.
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Decision Support Systems Course .. Dr. Aref Rashad
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Windowing
the task of organizing information depends on the kind of models, the
kind of decision maker, and the kind of environment in which one is
working.
use of the Windows standard for many products makes the design
of an uncluttered display easier
Windows can be sized and placed by the users so they can customize
their analysis of the information
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Decision Support Systems Course .. Dr. Aref Rashad
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Windowed Output
Representations
The goal is to show the results of some analysis
The appropriateness of the output depends on what the decision
maker expects to do with the information
Designers should take care to use rich visualizations that convey the
analysis most accurately and most efficiently to the user.
The appropriate output might be animation and/or video rather than a
display on a screen
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Decision Support Systems Course .. Dr. Aref Rashad
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Icon Options
Metriglyphs
Using Traffic Lights as Metriglyphs
Map of Sales Volume Drawn to Scale
Graphical Representation
Disaggregate Posting of Results
Minard’s Map of Napoleon’s
1812 Russian Campaign
The path of Napoleon's
retreat from Moscow is
depicted by the dark
lower band, which is
tied to temperature and
time scales.
So, by simply looking at
the graph, you can
discern the size of the
army and its location
and direction at any
time as well as the
temperature on some
days
Relationship Diagram
relationship diagram from a
social networking site showing
one person's contacts through
the site
Depth of Relationship Diagram
This particular diagram
illustrates all of the
companies (the darker
highlighted items) at
which we have placed
interns in the last year as
well as how many and
what kinds of other
relationships they have
with the department and
with each other (the
lighter highlighted
items).
It allows the decision
maker to see the depth
of the relationship, not
simply that there is a
relationship
Perceived Ownership of Analyses
Remind the users that they control the analyses and therefore the
decision-making authority
Provide users an easy way of changing the analyses if the results do not
answer the question appropriately or completely.
The use of icons on bar charts can leave inappropriate impressions
Another factor that can provide perceptual bias for decision makers is
the absence of aggregation of subjects when creating a histogram or pie
chart
Aggregated data can allow decision makers to generalize inappropriately
from the data.
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Decision Support Systems Course .. Dr. Aref Rashad
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On-Screen Analysis Change Prompting
Additional On-Screen Prompting
Scaling Deception
Distortion in Histogram
Individual Histogram
Aggregated Histogram
Use of International Symbols
Support for All Phases of Decision Making
Displays must be constructed so as to help decision makers through all the
phases in decision making
Intelligence
The decision maker is looking for problems or opportunities. The DSS
should help by continually scanning relevant records
Automatically notify productivity is low, absenteeism is high
Design:
Users are developing and analyzing possible courses of action. Displays
must be created that will help users generate alternatives.
Alert for violations of model assumptions, teleconference with employees at a
remote plant to initiate ideas
Choice :
DM selects a course of action from those available.
Compare and contrast the various options, Prompt users to complete
sensitivity analysis
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Decision Support Systems Course .. Dr. Aref Rashad
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Knowledge Base
The knowledge base, as it refers to a user interface, includes all the
information users must know about the system to use it effectively. We
might think of this as the instructions for systems operation, including how
to initiate it, how to select options, and how to change options
In the DSS context, there are additional ways of delivering the knowledge
base. One popular mechanism is training by example. The user is taken
through a complete decision scenario and shown all the options used and
why
This means there must be ways for experienced users and inexperienced
users to obtain the kind of help they need and the training and help must be
for specific techniques and models.
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Decision Support Systems Course .. Dr. Aref Rashad
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An Alternative Menu Format