Collect Data: Identify Types of Data (Categorical or Numerical) . Data types are an important part of statistical analysis. The type of data that will be collected by asking a particular question will influence the data collection methods, representation, and analysis of that data. Data can be either categorical or numerical. . Categorical data is data that is words or categories. Numerical data is numbers. Categorical data is qualitative and analysis needs the pieces of data to be sorted into c