In LimeSurvey, for each question that is created in a survey a chart type can be predefined in the statistics options of the respective question. If not changed, it will be set to bar chart by default.
Not to worry though, in the statistics overview after collecting survey responses, you can simply and flexibly switch back and forth between all available chart types.
Besides bar, pie, donut and line chart, LimeSurvey offers a few more chart types that are not as mainstream: radar (spider) chart and polar chart.
Radar charts are a great way of visualising multivariate data, i.e. data with multiple variables, on two dimensions while the variables are represented by axes starting from the same point. Thus, radar charts are beneficial when other chart types such as bar charts become rather cluttered with an increasing number of variables.
Polar charts are essentially radar charts since both display data as circular graphs and can be used nicely for visualising multivariate data. However, while radar charts connect the variable results to a "web", the polar charts display results in adverse bars within the circular diagram.
General tip: keep the number of variables in your radar or polar chart to a maximum number of 8 to avoid chart overload and confusion.
Advanced tip: if you are dealing with great amounts of survey data in general, we recommend you consider creating pivot tables to get more efficient and structured data filtering options when generating flexible and powerful pivot charts.