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The Psychology of Notation

January 10th, 2009 by Joseph P. Merts

Symbolic and Numeric RatingsThere has been much debate over which representation is the best to use when filling in the ratings for a House of Quality: symbolic notation or numeric notation. The premise behind the debate is that there is somehow a greater inherent value in using circles, filled circles, and triangles or in using 1’s, 3’s, and 9’s. In actuality, neither format is universally superior to the other. On the contrary, they both serve different purposes and are uniquely suited for working with different groups. Thus, just as it is important to tailor a speech or written argument to the needs of the intended audience, it is important to choose the notation for a QFD that is best suited for its target audience.

The Magnitude of the Measurement

The choice of notation formats depends largely on how much attention one wants to draw to the relative magnitudes between rating values. If an engineer or product manager wishes to encourage more careful analysis of the relationships, then numeric notation is often a better choice. Viewing the exponential scale while one is rating often helps stake holders to be more judicious in assigning “low” and “strong” relationship values.

By the same token, if a QFD practitioner is worried about inducing “analysis paralysis” among the targeted stake holders, then symbolic representation is probably the preferred notation. Symbolic notation often shortens the perceived chasm between “moderate” and “strong” ratings, and helps to reduce the reluctance felt by some stake holders to provide decisive ratings.

Mathematician or Marketer

Another factor to consider when choosing a QFD notation style is the technical and/or mathematical aptitude of the target audience. Numerical notation is often more appealing to technical audiences such as engineers and scientists who like to understand the algorithms involved in the House of Quality. These audiences frequently prefer numeric notation because it replaces “magical” ranking behavior with a comprehendible scientific process.

Symbolic notation, on the other hand, is often more appealing to business, marketing, and sales individuals. These stake holders are often distracted by numeric notation and begin to view a Quality Function Deployment as a “numbers game” when presented with numeric notation. Using symbolic notation often helps these target audiences to focus on the simple relationships between requirements, rather than on the numbers and calculations involved in a House of Quality. Symbolic notation helps these stake holders view a Quality Function Deployment as the communication tool that it is rather than as the mechanized dictator that it isn’t.

Playing to the Audience

The choice of notation when constructing a Quality Function Deployment can have a major impact on the audience involved. Numeric notation is better suited for teams that are technically-oriented and/or teams that need to focus more carefully on their ratings. Symbolic notation is more appropriate for less-technical audiences and/or audiences that are prone to endless debate over individual ratings.

In truth, there are many characteristics of a QFD that can and should be modified to meet the needs of the audience involved. Different audiences require different communication mechanisms, different meeting frequencies, different meeting durations, different leadership styles, and even different tools. However, when one is tailoring his or her Quality Function Deployment to meet the needs of its stake holders, notation style should not be overlooked. For when it comes to making team members comfortable with a House of Quality, using 1’s, 3’s, and 9’s has a substantially different affect than do circles and triangles. Indeed, when representing a “moderate” relationship in an HOQ matrix, one will likely find that “to three or not to three—that is the question”.

This entry was posted on Saturday, January 10th, 2009 at 10:00 am and is filed under House of Quality, Advice, Quality Function Deployment, QFD. You can follow any responses to this entry through the RSS 2.0 feed. You can also leave a response.

1 response about “The Psychology of Notation”

  1. Veenstra said:

    Great!!! I had some scans, some things to work with in groups, but this is great! Also the explanation is understandable and direct. For my students in the Netherlands it will be of much help, denoting also that they seem more keen on learning from the web than from a book!

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