12.07
Quality Perception: Multiple Attributes – Single Acceptance
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Klik : quality perception multiple attributes single acceptance
QUALITY PERCEPTION
Can we perceive quality? Do we have a sense to distinguish good from bad
quality? Being educated or not, everybody has an imagination of good or bad of almost
everything in his environment. As long as a minimum of attention and involvement is
exerted to an object, a feeling of pleasantness or unpleasantness is almost simultaneously
present. Even more than optical or acoustic signals the experience of odours and flavours
lead almost inevitably to an affective tone. We hardly can imagine eating a food without
knowing instantly if we like it or not. And when we ask someone, how a food tastes, we
expect and will receive the answer “good” or “not good” rather than “sweetish”, “salty”
or like something else.
Many of these quality experiences are well memorised, and we almost have the
impression, even before we envision the details of an object or event in the past, we have
a notion whether it was good or bad. But things can change. What was pleasant yesterday
must not be felt as pleasant today. Especially in case of food we might have eaten too
much of a specific item or consumed it too frequently. In addition, there is also a
cognitive side of quality assessment. Food scandals, information on improper production
methods or ethical considerations may affect the quality judgement. Product image
associations, the price of a product or the availability of alternatives are examples for
quality cues, too.
More and more these contextual, “external” attributes came into the focus of
quality researchers, as important for quality evaluation and were denominated as extrinsic
properties, as opposed to intrinsic properties, which refer to the attributes, physically
belonging to and being verifiable in the product item itself. Those attributes, detectable in
the product were the objects of the traditional quality research. Amongst the plenty of
product properties often attributes were selected as quality criteria based on their
measurability, accuracy and precision rather then a verified relevance for acceptability
(Shewfelt, 2000) thus contributing to consumer oriented quality.
MULTIPLE ATTRIBUTES
Attributes of products are the elements, which are perceived through the senses of
sight, smell touch, taste and hearing. Thus they are the first step from product itself to a
recognised item. Widely accepted, the definition of sensory evaluation is: evoking,
measuring, analysing and interpreting human responses to those perceived sensations
(Stone and Sidel, 1993). This definition was valid also in the early beginning of sensory
investigations in the 19th century. But the focus was on the product (stimulus) side, rather
than the response side in terms of complex food or consumer matters. The starting point
was detecting the amount of a physical stimulus to be perceivable and, when further
increased, to be perceivably different. Fechner introduced these “just noticeable
differences” as a unit of measurement, which allowed to construct a relationship between
a stimulus and the sensory intensity. With his book “Elemente der Psychophysik” from
1860 he laid a foundation stone for sensory science and was among the first experimental
psychologists at all.
From stimulus to sensation
The new science: psychophysics established the functional relationships for
various stimuli and the intensities of the sensations. Fechner developed a relationship,
built on the constant just noticeable differences, used as a unit for expressing the
Proc. Int. Conf. Quality in Chains
Eds. Tijskens & Vollebregt
Acta Hort. 604, ISHS 2003