Transcript
By Muhammad SajjadPH# 03346544625
Contents
Definition
Explanation
Types
Requirements for modeling
Merits and demerits
References
Model in Geography
The world model is derived from French word “modele”, Italian word
“modello” and Latin word “modulus” means model.
Meanings of model
There are two meaning of model
1. Real or Original: It represents real things. For example; building,
car and aircraft and ship etc.
2. Ideal: It represents the ideal things. For example; ideal teacher,
ideal friend and ideal hero etc.
Definition of model
In 9465 Peter Haggett defined the model as, “a simplified version of
reality, built in order to demonstrate certain of the properties of
reality".
In French language it is defined as; “simplified representation with a
view to demonstration"
By Alain Rey, the model is a "system representing the essential
structures of a reality".
Explanation
After the reading of all these definitions it is right to say that
model is a simple representation of reality or it is also called analogy.
The models used in geography come from elsewhere. This is partly
true. So, others may have worked better and earlier than we have. It
is therefore intelligent and fruitful to take inspiration from their ideas
when these contribute to our understanding of the production of
geographical space.
This is not a reason to forget that geographers have produced an
abundance of their own models, which are no less useful: piedmont,
huerta, estuary region, frontier, march, dead ground, distribution
models of free ports and tax havens, and world megalopolises.
Furthermore, some imports and analogies are worth being re-
exported.
In the view, the gravity model (the bigger and the closer, the more
attractive) is infinitely easier to understand in geographical space
than in cosmic space, simply because, in everyday life we clearly
understand the reasons, i.e. the nature of the "energy" in question.
Modelers are dangerous, because their ambition is prediction and
application and they want to force reality to fit their models.
Apparently Christaller tried to persuade Hitler to "rectify" the
network of Polish towns to coincide with his model. Even if true—
and the anecdote needs to be verified—the undertaking did not
succeed.
At the same time, a plethora of territory-makers, neither
geographers nor scientists, have attempted, sometimes successfully,
to design or redesign spatial organizations to meet their
requirements. This has nothing to do with the idea of models, except
in the vulgar, prescriptive Sense of the word. This argument is simply
groundless accusation and is even comical in that it credits
geographers with powers they have never had.
Types of models
Ackoff (1962) differentiates between iconic models, which use the
same material but involve changes in scale, analogue models which
also involve a change in material used in building the model.
Symbolic models which represents the reality by some symbolic
system such as a system of mathematical equations. Each type of
model varies in its appropriateness for different functions. In next we
will study these types of models one by one.
Iconic models
This type of model shows three dimensional characters. For example
length, width and height of the feature that is photograph, map and
globe. They are simple represntator of reality
Analogy / Conceptual
When one phenomenon is represntated by other
phenomenon. Real things have become points on the Map. They are
abstraction and most models include in this group. These models are
use to represent the social conditions of a society in the form of
deferent concepts. For example; movies and dramas.
Symbolic models
The representation of a phenomenon or a situation with the
help of mathematical symbols is termed as mathematical models. In
this models different features and their relationship is shown in the
form of symbols.
Example
dN /dT=rn(1−¿N /k )¿
N= population size T= time period
K=max. Population size possible
r= growth rate
Requirements of models
Identity and identification
To define a geographical object, place, country, field or
distribution, is to describe its singularity or, in other words, its identity.
But how do we describe an identity and what does this word mean?
Identity comes from idem, the same. We define an identity by observing a
similarity. This is an interesting paradox, and a logical one: we can only
define something in reference to known models.
Tall, strong, blond, blue eyes, red skin, turned-up nose and round face are
elements of identification which, in sufficient number, will describe a
singular person. This description is based on a selection from among
general, common, inventoried, understood features.
Meaning.
To advance, these models must have meaning. Recognizing forms
implies that we understand where they come from and what produces
them. The subject is also complicated by phenomena of convergence:
identical forms can have different origins, and vice versa.
The geographer must at least make a conscious effort to recognize and
interpret spatial forms. This is the difference between science and
esoterism. The geomancer, astrologer or augur who "reads" coffee grinds,
a palm or a chicken’s innards observes forms whose origin bears no
relation to the question asked.
They are the only ones to "see" (or imagine), but they claim to have the
gift of trance and divine inspiration. Geographers, usually devoid of both,
use known forms, for which they have learned the logic of production
(whether of social or natural origin), even if they sometimes have to
discover new forms.
Merits
Models are more near to reality.
Brief description of a reality.
Models provide linkage between many physical features.
Models are pillars of research or theory.
Models help us to prepare the planning ahead.
De-merits
Simplest description of reality
Models have narrow impact of theories
Very hard to construct in very defined size
Data may not available of subject
References
HAGGETT P “Geography a Modern Synthesis” 3rd
revised Harper and row NEWYORK
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fundamentals/chapter4.html
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