| Variables | Number of categories | Mode | Frequency mode | Categories |
| Classification according to argilosity and compressibility | 7 | Mineral clays with low plasticity | 135 | Mineral clays with low plasticity |
| Mineral clays with medium plasticity | ||||
| Mineral clays with moderate plasticity | ||||
| Plastic mineral clays | ||||
| Mineral silts with intermediate compressibility | ||||
| Mineral silts with medium compressibility | ||||
| Mineral silts with low compressibility |