Quantitative Descriptive Analysis

The choice depends on the attribute and panelist sensitivity. Most QDA studies use 15-point unstructured line scales because they provide fine discrimination. However, shorter scales (9-point) can be used for simpler attributes or faster testing. The key is that the scale should be sensitive enough to discriminate between samples but not so long that panelists cannot reliably place their responses.

QDA and consumer testing serve different purposes. QDA provides an objective, detailed sensory profile of what is in a product; consumer testing measures liking and acceptance among the target population. QDA is useful for identifying which sensory attributes drive consumer preference, but you need both methods for product development. Many companies use QDA to optimize formulations, then validate with consumer testing.

This depends on the intensity of use and consistency. If panelists evaluate samples frequently (weekly or more), recalibration should occur every 4-8 weeks. If evaluations are infrequent, refresher training quarterly or semi-annually is adequate. Regular evaluation of panelist agreement and repeatability helps identify when retraining is needed.

QDA involves intensive training and uses predefined attributes with reference standards, resulting in high consistency and reproducibility. Flash Profiling is faster—panelists generate their own descriptors and rate them without formal training. Flash Profiling is quicker but less standardized; QDA provides more repeatable, comparable data across time and locations.

Typically, 10-20 trained panelists are used. With fewer than 10, you may not have enough statistical power; with more than 20, you gain little additional benefit but incur higher costs. The exact number depends on the variability of attributes and the statistical tests planned.