simultaneously by evaluating a “loss-of-fit” criterion. Multivariate adaptiveregression splines also search for interactions between variables, allowing any degree of interaction to be considered. It uses adaptive regression,
guiding the function being estimated by the local nature of the data. Where
RTA excels at detecting local data structure and marginal interaction
effects between predictor variables, MARS excels at detecting global and
linear local data structure, flexibly modeling relationships that are additive
or that involve interactions between predictor variables (Prasad and
Iverson 2001). The discontinuous branching of RTA is replaced with a continuous, smooth response surface. Multivariate adaptive-regression splines
provide an automatic, nonlinear stepwise regression tool that is particularly useful where variables need transformation and where interaction
effects are likely to be relevant.
8.3.1.7 Providing Improved User Interfaces to Make Models Accessible
Ease of use is a key criterion for the acceptance or rejection of a model by
managers, and the user interface provides the biggest opportunity for the
modeler to improve ease of use. Most users of computer software now
expect a graphical user interface (GUI). When the GUI is designed to be
intuitive, consistent, and not redundant and to have a logical flow, potential
users will be more likely to explore the utility of the model (Jacucci et al.
1996). A large number of GUI-development software packages are available to aid the construction of GUIs for models coded in almost any highlevel language. A model GUI may also feature sophisticated graphical or
animated output of model results, making them more readily interpreted
and allowing more efficient evaluation of multiple model runs (e.g., see
Figure 8.4). Object linking and embedding (OLE) and dynamic data
exchange (DDE) are capabilities to embed or link data from one application software within a file of another software package. Dynamic data
exchange might be used to link a spreadsheet model to a simulation model,
for example. Hypertext markup language (HTML) and other Web-oriented
code can be used to allow distributed modeling over the Internet. Spatial
models are often constructed with a custom user interface (e.g., ArcView
extensions). A common result of an enhanced user interface is an improved
likelihood that decision makers will apply the model.
8.3.1.8 New Computational Technologies
Our discussion has alluded to the limits of computational technology on the
development of ecological models. Computational science has combined
elements of computer science, information technology, scientific modeling,
and numerical analysis to allow new approaches to old problems previously
handled by approximations and to deal with new problems previously
considered intractable. Distributed computing combines the computing
resources of separate machines that may be collocated or physically distant
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guiding the function being estimated by the local nature of the data. Where
RTA excels at detecting local data structure and marginal interaction
effects between predictor variables, MARS excels at detecting global and
linear local data structure, flexibly modeling relationships that are additive
or that involve interactions between predictor variables (Prasad and
Iverson 2001). The discontinuous branching of RTA is replaced with a continuous, smooth response surface. Multivariate adaptive-regression splines
provide an automatic, nonlinear stepwise regression tool that is particularly useful where variables need transformation and where interaction
effects are likely to be relevant.
8.3.1.7 Providing Improved User Interfaces to Make Models Accessible
Ease of use is a key criterion for the acceptance or rejection of a model by
managers, and the user interface provides the biggest opportunity for the
modeler to improve ease of use. Most users of computer software now
expect a graphical user interface (GUI). When the GUI is designed to be
intuitive, consistent, and not redundant and to have a logical flow, potential
users will be more likely to explore the utility of the model (Jacucci et al.
1996). A large number of GUI-development software packages are available to aid the construction of GUIs for models coded in almost any highlevel language. A model GUI may also feature sophisticated graphical or
animated output of model results, making them more readily interpreted
and allowing more efficient evaluation of multiple model runs (e.g., see
Figure 8.4). Object linking and embedding (OLE) and dynamic data
exchange (DDE) are capabilities to embed or link data from one application software within a file of another software package. Dynamic data
exchange might be used to link a spreadsheet model to a simulation model,
for example. Hypertext markup language (HTML) and other Web-oriented
code can be used to allow distributed modeling over the Internet. Spatial
models are often constructed with a custom user interface (e.g., ArcView
extensions). A common result of an enhanced user interface is an improved
likelihood that decision makers will apply the model.
8.3.1.8 New Computational Technologies
Our discussion has alluded to the limits of computational technology on the
development of ecological models. Computational science has combined
elements of computer science, information technology, scientific modeling,
and numerical analysis to allow new approaches to old problems previously
handled by approximations and to deal with new problems previously
considered intractable. Distributed computing combines the computing
resources of separate machines that may be collocated or physically distant
148
Eric Gustafson et al.