Problems Affecting Overlays:
The Modifiable areal unit problems
The modifiable areal unit
problem (MAUP)
occurs when
arbitrarily defined boundaries are used for the measurement and
reporting of
spatial phenomena. This means that the value of the entity
recorded varies continuously over space. Although individual people are
measured in population censuses, data are normally reported for areas.
Thus, changing the boundaries of units and disaggregation or
aggregation can affect the appearance of the data set.
Ecological Fallacy
A problem associated with
MAUP is the
ecological
fallacy. This occurs when it is referred that data for areas under
study can be
applied to the individuals within those areas. For example, if analysis
of
geodemographic data identifies the average income level in a postal
zone,
it is
an ecological fallacy to assume that all individuals within that postal
zone
have that level of income.
Selecting Threshold Criteria
Visual
Complxity
When two complex maps are
overlain the output is likely to be more complex than either of the two
input maps. The more complex of a GIS output, the more difficult to
interpret. Therefore, generalization is used for the output layers and
analysis.
Although,
this project
has taken into account many aspects regarding the placement of a
Mountain
Equipment Co-op store in
Additionally, the
investigation is limited due to the fact that the project is a
hypothetical
analysis. Knowing the actual number of
MEC members within
A level of inaccuracy
also exists in the analysis due to restraints in knowledge, resources,
and
time. Because Mountain Equipment Co-op
is known abroad by most outdoor enthusiasts, the analysis may be
more
accurate if conducted on a regional level rather than a metropolitan
level (for example
with DA census data for