On the naming of parts

by Bernie Cohen
The field of modeling is rich in terminological confusion and misunderstanding, in which some of the terms have formal definitions that are radically different from their everyday usage. An eminent MIT Professor of Engineering used to introduce his students to the subtle concepts of precision, accuracy and significance with the following (non-PC) example.

  • You ask a lady her age and she tells you she is 35. This statement has a precision of plus or minus 6 months, could be inaccurate by as much as 10 years and, if she is attractive, has no significance whatsoever.

What follows is an attempt to cast some light on the terminological confusion and misunderstanding.

The ‘I’ of the beholder

by Philip Boxer
With the first two asymmetries, what is particular about the customer’s relation to his or her context-of-use can be aggregated out, so that the ‘I’ can be asserted unilaterally. But with the third asymmetry, it cannot, so that the ‘I’ has to be established collaboratively…