WSP00452

• File Number: 8200.766
• Description: Gunnison River Basin General Publications - Correspondence - Reports
• State: CO
• Basin: Gunnison
• Water Division: 4
• Date: 10/27/1992
• Author: Unknown
• Title: Gunnison Basin Models - Planning Model - 1991-1992 - Draft Functional Specification - Gunnison River Basin Planning Model
• Water Supply Pro - Doc Type: Report/Study

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Functional Specification for the Planning Model

User Interface Design Objectives

The design of a "user interface" for a computer program encompasses all aspects of how
the "end user" obtains useful information or results from the program. A traditional user
interface for a model of a hydrologic system might involve a time-consuming process of
communication between the end user and a technical conSultant, who would modify and
actually operate the model and provide the output together with analysis and conclusions to the
end user. The technical consultant might operate the model by making changes to a
combination of computer "files" containing code, data and commands, which would be obscure
or incomprehensible to the end user.

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Generally speaking, the advantages of the traditional approach are the freedom the end
. user enjoys in formulating hypothetical situations to be simulated and the freedom the
consultant has in tailoring the model to address a particular set of questions. The end user also
benefits by saving the design and implementation costs of a more general model and of more
convenient means for operating the model.

Disadvantages of the traditional approach include the following:

1. The cost of the consultant's time for performing each model run, even
if partially offset by lower initial design costs, inhibits the end users
from making full use of the model.

2.

The leadtime required for end users to obtain results from each
successive model run inevitably limits the potential value of the model
as a vehicle for exploring and learning about the real-world system
represented by the model.

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3.

The tendency of a traditional model to evolve as new questions are
presented means that there may be uncertainty about the degree to
which current and previous results are genuinely comparable.

4. The consultant's limited capacity to perform model runs inevitably
restricts the number of organizations having an opportunity to specify
scenarios and to explore planning issues from their own perspectives.

5. The separation which is maintained between the end users and the
model limits the extent to which the end users can develop an
understanding of the model and, therefore, develop confidence in the
results produced by the model within its proper scope of application.

Compared to these advantages and disadvantages, it is clear that the objectives for the
Gunnison Basin Planning Model dictate a very different type of user interface from the
traditional approach. The primary user interface criteria for the Planning Model are as
follows:

I. Each end user should be able to operate the model without assistance
and should be able to fashion his own approach to exploring those
questions which are of greatest interest to him.

2.

All end users should be able to get comparable answers to comparable
questions, or should, at least, be able to understand how their different
interpretations of a question led to different results. To this end, the
model should automatically document differences in assumptions used
in different model runs.

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