Questions selected for an Index question can be assigned different weights. The weight values are added for each question, assigning a numerical value, where the sum of all weights needs to be 1 and the decimal separator used is “.”.
How it’s calculated
Dapresy calculates index questions with weights in a different way than regular index questions. First a mean value over each question in calculated. Once all questions have a mean, the weight for each question is multiplied with each mean and the sum of these values creates your index. See the example below.
If weighted data in objects is used, each answer is multiplied with its respondent weight before the question mean is calculated. After that, the system multiples the mean with the weight for that question and the sum of these calculations is the Index.