For example, if age, height and weight are recorded for each person, group these as individual cells in a row in a table, or as items in parallel lists.
Data in a model should be grouped to allow for clarity e.g. a model of atmospheric measurements taken around the world could be grouped by the date taken and organized on one row of a model. Grouping of data could also be used to find trends in data and see the correlations
Data about student performance should be grouped in rows for all the students assessments