Multivariate analysis enables a view of the positive and negative correlations between criteria based on voting results. Note that Multivariate analysis compares criteria. To view correlations between items use CrossTab Chart.
There are three possible ways to view the information:
- In a table.
- In the circles chart.
- In the network diagram.
Correlations may be strong or weak and positive or negative.
Using two Criteria, the first "Important" the second "Likely to be done", if the responses from voting show that Ideas voted more "Important" were also voted more "Likely to be done" then there would be a positive correlation.
If the responses from voting show that Ideas voted more "Important" were voted less "Likely to be done" then there would be a negative correlation.
The criteria are considered highly positively correlated when the votes match more closely than when they do not and highly negatively correlated when the results are opposite or close to the opposite.
- To view Multivariate Analysis go to Vote & Report > Charts >Multivariate.
- The default view is the circle chart. To toggle between circle, network and table, choose View and the appropriate option (see descriptions below).
- Results may be filtered by stakeholder group by using the Tools > Filter by Stakeholder option.
Multivariate Analysis Display Options
The two main display options are:
Highly correlated items are shown with large circles, less correlated with smaller circles. Positive correlations are indicated in red and negative correlations are blue. Shading and sizing vary to show the comparative correlations between all the criteria. Numerical values between -1 and +1 also represent the strength or weakness of the correlation and whether it is positive or negative,
Network is a feature that combines all of the correlation data and presents it as a single picture. If two Criteria are strongly positively correlated, they are positioned close to each other and linked with a red line. If two Criteria are strongly negatively correlated, they are positioned close to each other and linked with a blue line. If two Criteria are not correlated at all, they are then positioned as far away from each other on the screen as possible. Network attempts to place all of the Criteria on a plane following the rules above.
Tension is an arbitrary measure of how far the current arrangement of Criteria boxes departs from an optimum. If you shuffle and the tension does not change, Ballot has found the best arrangement it can, based on the data you have collected.
From the sub-menus available on the chart, choose View > Format Settings to select colors and fonts.