Читать книгу Medical Statistics - David Machin - Страница 31

In some studies it may be appropriate to assign ranks. For example, patients with corns may be asked to order their preference for treatment, for example, hard skin (corn) removal by scalpel; special rehydration creams for thickened skin; customised soft padding or foam insoles; corn plaster containing salicylic acid. Here although numerical values from 1 to 4 may be assigned to each treatment we cannot treat them as numerical values. They are in fact only codes for best, second best, third choice, and worst.