You can combine the results of surveys of the same type (or nearly of the same type). In this way, it is possible to collect the results of a survey carried out at regular intervals in one place, for example.
Results can also be imported from an Excel file. (Contact customer service for more details.)
Merging and comparing data is sensitive to changes in question options. If you have, for example, a 2013 and 2014 surveys with same questions, but the questions options differ from each other the results can be shown wrong. For example, 2013 survey ask gender with options 1: Male and 2: Female and 2014 survey asks the same gender question with options 1: Female and 2: Male. If the 2013 survey is merged to 2014 survey for comparison the 2014 survey gender question shows the 2013 results as 1: Female and 2: Male.