Specificities analysis (multivariate) (AskiaAnalyse)

This is a descriptive analysis that allows you to prioritise the variables that best describe a category of a population. It is used on closed variables (single, multi-coded or scaled responses) when there are n > 30 in each category. The higher the probability, the more the variable contributes (chi²) to this category. The more the group depends on this category, the more this category will explain this group.

We obtain the percentage of each response in the population (group). This observation is normalised and displayed on the sigma (Z) and the probability. In terms of interpretation, the higher the sigma (> + 2), the more the modality explains the group (= high probability 100%). When sigma is < -2, this means that this method does not explain the whole group (we also found a small number of people who have answered this code in the group).

This statistic follows a standard normal law.

To perform a specificities analysis:

1. In the general tab, select specificities.
2. Add a single-coded, multi-coded or scaled response question to the to explain tab (for example, drag and drop them from the questionnaire list).
3. Add several single-coded, multi-coded or scaled responses questions to the descriptive tab.
4. Click results to view the analysis.

One page of results is generated for each category in the question you added to the to explain tab. When you open a page, you will see the counts, percentage, sigma, base and significance for that category. In the following example, we want to describe the category Overall appreciation of the film: Not at all:

Note that the first item which explains this category is Film I would wait for watching on TV: Not at all: 38.3% of 255 (the total population) are in this category. We are sure at 100% because the sigma is high (5.20).

You can change the specific settings used for the analysis. To do so, click analysis options.... For details, see multivariate analysis options.