Paired, parallel, or profile plots showing the values of two variables may be constructed readily using a combination of graph twoway commands. This column explores the principles and practice of such plot-making, considering both wide and long (panel or longitudinal) data structures in which...

Many statistical problems involve comparison and, in particular, the assessment of agreement or disagreement between data measured on identical scales. Some commonly used plots are often ineffective in assessing the fine structure of such data, especially scatterplots of highly correlated...