Interval-valued fuzzy sets aggregation and evaluation approaches

We review interval-valued fuzzy sets (IVFS) and develop their application for several areas. We show how to aggregate IVFSs and provide information measures to guide the aggregation. An example of the use of IVFS to represent the uncertainties in Covid-19 contact tracing is illustrated. Then we consider the application of IVFS in spatial data. By determining distance and area of IVFS data we can use aggregation to apply this to minimum bounding rectangles for GIS. Finally, IVFS can be applied in computing diversity in the process of selection of groups exhibiting diversity.