Adding ordinal dummies into an interval index is more arbitrary than fuzzy-logic transformation.

Evidence

Some might object to the fuzzy-logic transformation of ordinal to ratio, described above as being “arbitrary.” However, I would suggest that converting a bunch of ordinal dummy variables into an interval index via addition is more problematic and arbitrary. — Gary Goertz, Social Science Concepts and Measurement, 835

Categorization

• QUESTION: Is this defensible? Fuzzy-logic calibration involves researcher-chosen thresholds and crossover points, so the ‘arbitrariness’ tradeoff deserves scrutiny.