An environmental scientist investigating river quality records the concentration of a chemical pollutant. Rather than recording the precise numerical concentration in parts per million (ppm), they classify each sample into one of three categories: 'Low', 'Medium', or 'High'.
Identify one statistical limitation of using this qualitative categorical data compared to the original quantitative measurements.
235 exam-style questions on AQA A Level Psychology Data handling and analysis. Each one has a worked solution and a mark scheme showing where the marks go.