STANDARDIZED PREFERENCE INDEX FOR MEASURING INDIVIDUAL FOOD CHOICES

Standardized indices (I) have been created to determine and analyze individual food preferences in choice tests between A types of food presented in the form of N items entirely consumable within the course of one test. For each food type, I represents the ratio between the cumulative area under the curve of the proportion of items consumed as a function of the order in which are consumed the A.N items, and the sum of the areas for all A items. 1 varies from 0 (for food in which no item is consumed) to 1 (for food items consumed exclusively); I = 1/A for A types of food for which there is no preference; the sum of all indices (I) for all A foods equals 1 in all tests. These standardized indices have been used in tests on Barbary doves (Streptopelia risoria) to study intra-individual coherence and interindividual correspondance in reference to preferences for canary grass (Phalaris canariensis L.), oats (Avena sativa L.), wheat (Triticum vulgare Vill.), hemp (Cannabis sativa L.), and millet (Panicum miliaceum L.).