Categorical Data 101 There are two main types of data: categorical and numerical. Numerical data, as the name implies, refers to numbers. Categorical data is everything else. As its name suggests, ...

Data clustering is the process of grouping data items together so that similar items are in the same group/cluster. For strictly numeric data, the k-means clustering technique is relatively simple, ...

Categorical and numerical data are common in dental research and they may be analysed, presented or summarised by a variety of methods including: Proportions (eg, percentages).