and also where Clausse's model is presented
At this stage we will attempt to discuss more in depth
the significance of the noise values in our model.
Given visual noise values are assumed in our model to be a product of the
area covered by the elements of the noise source and a proportionality parameter.
Designating the later area by AN and the total area ( that is the area under the field of vision) by A, the fraction F is given by AN /A ,and the noise value N is given by:
N = K * F (3)
where K is a proportionality parameter. The fraction F can have a maximum value of 1 and a minimum practical value of 0.05 ( a value of zero is avoided for numerical
reasons since N=0 will make the SNR to tend to infinity).
The values of K will be positive integers in the range 1-100. A given noise value,
say N=10, could then be the result of a number of different pairs of fractional area
and constants. Formula (3) is used to introduce in the model the fact that the same
fractional areas of various noise sources can give rise to different noise values,
depending on the "impact" of the visual perception of the element in question.
If we fall back on the example of a patch of lawn, it is obvious that a section of
dry yellowish grass and a bunch of empty tin cans, covering the same fractional
area will give rise to noise signals of widely different intensities. The parameter K
is then a way of giving different weights to various noise sources of the same size.
Values of F can be easily determined from photographs of the field of vision by
planimetry but values of K have to be chosen more or less arbitrarily, according
to the properties of the noise source. In another section we will atttempt to propose
survey methods to produce scales of K values for different elements but it is clear
that a lot of further work will be rquired to put these values on an experimental basis.
If, as is often the case, noise sources of different kinds are present in a garden unit,
we assume in our model that the value of the outcoming noise signal will be the sum
of the contributions of the various elements.
In order to obtain a greater understanding of visual noise in gardens a consideration of Clause's model of differential audience reach might be of help:
known as model for differential audience reach (3). Although originally designed
for a radio broadcasting situation, the model, like any other good model, can be applied to a wide range of situations. It is presented in schematic form in Diagram 5 below:
and largest represents the audience that could be reached by the message offered by
the radio station. The audience could be quite large but the message is receivable,
(second square) only by those within the area of good reception and that have radio
sets. Within this potential audience the message is received only by those that have their radios on and tuned to that particular radio station. A fairly common situation is
that of persons having their radios on but not paying any attention to the music or the
words, the fourth shell represents that part of the former audience that actually register
the message (difference bet. hearing and listening). The smallest and innermost
rectangle represents that part of the former audience for which the message is
internalized that is results in a change in the condition of mind. The change could be
of an induced emotion, an elaboration of a political wiewpoint or a decision to buy
something that is offered (which is after all what publicity firms are looking for).
In the case of audiences for gardens the model may be applied thus:
a garden unit is there for everyone to see, that is the message offered by the garden.
But the message is receivable to those that happen to pass by. Of that potential audience, the message is received only by those passers by that happen to look at it.
As they say, "to look is not to see" and that part of the audience for which the message
is registered is formed by those persons that actually " see " the garden, the shapes,
the colors,etc. For an even smaller part of our audience the message from the garden
is internalized and results on new information or in a sensation of well-being or pleasure
and even into an emotion caused by the perception of beauty.
In the context of this model, the main function of the system is to produce
an offered message with a high SNR so as to insure that the message received will be
registered and even internalized. If this is the main function then a Gardener should devote a lot of attention at the factors that affect the reception, registration and
internalization of the offered message.
similar lines: The message received at the Destination may or not be registered depending on the degree of attention or awareness of the Observer. In addition, also the susceptibility of a given Observer to a particular type of disturbance will play an important role. Weeds for instance, particularly if they are small, may or not be registered as a disturbance depending on the gardening background of the Observer.
Cigarette butts on the ground may be more offensive to the non-smoker. Assorted litter
inside a garden will be more striking to a person with tidy habits. The same is valid
for the passage from registered to internalized message.
What we are implying is that the constant K of eqtn. 1 is very much dependent
on the cultural background of the Observer. We must we aware that when attempting
to build a scale of K values for different noise sources the scale will not be the same
for different countries or even for different sectors of the public within one country.
A pretty rose may be considered pretty all over the world whereas an empty bottle nearby may be ignored by some or looked upon with utter disgust by others.
Message
Received
Message
Internalized
Message
Registered