Page 81 - Software and Systems Requirements Engineering in Practice

52 S o f t w a r e & S y s t e m s R e q u i r e m e n t s E n g i n e e r i n g : I n P r a c t i c e

Ethnographic Techniques
Ethnographic research tends to focus on a particular community or
culture [Agar 1996]. Typical collection methods are interviews and
surveys. These are techniques not normally thought of as being a part
of requirements engineering, yet some survey methods are heavily
used to evaluate market demands, possible interest in a product, and
even emotional content. Furthermore, where there is a large customer
base to draw on, it is possible to perform statistical analyses on
surveys to measure customer interest or the emotional appeal of
product features. One of the most common survey methods for
analyzing customer interest in features is Kano modeling, named
after its inventor, Professor Noriaki Kano [Kano 1984].
Kano modeling provides three variables to measure customer
interest: one-dimensional, expected, and attractive quality. One-
dimensional, or linear quality, applies where the potential value of a
product feature increases linearly with some aspect of the feature. A
good example of this is refrigerator energy efficiency. The more efficient
the refrigerator is, the greater the likelihood it will attract purchasers.
Expected quality is a feature that is mandatory for a product to succeed
in the marketplace. Attractive quality is a feature that is not expected
but would add to the emotional appeal of a product. Product features
can have different types of Kano quality variables, depending on locale,
targeted market, and time. For example, a camera in a cell phone would
have been an attractive quality several years ago but is now an expected
quality in most markets.
One interesting aspect of Kano modeling is that measurements
can be culturally sensitive. For example, in the United States most
automobile customers would expect to purchase a car with an
automatic transmission, while in Europe, a manual transmission is
the norm. Kano modeling is widely accepted; some commercial
requirements engineering management software tools come with
Kano analysis facilities built in.
Another interesting use of survey and interview techniques is the
measure of the emotional appeal of a product feature. Engineers and
software developers are often not aware of or interested in the
emotional appeal of their products, yet such factors can have
important consequences for product sales. One extreme example of
failing to take emotional appeal into consideration is the case of the
Ford Edsel. The Washington Post called it the “The Flop Heard Round
the World” [Carlson 2007]. After the car was introduced, customer
response was extremely negative, including comments such as “an
Oldsmobile sucking a lemon” and “a Pontiac pushing a toilet seat.”