Run charts are similar in application to control charts. We are interested in finding nonrandom patterns in data over time. These patterns are identified as either runs about the median, or runs up or down. These rules identify clusterings, mixtures, trends, or oscillations in our data.
In this example, we will plot the time in the office of all the US Presidents. For ease of use, this data is supplied in a Minitab worksheet. The data was gathered from Wikipedia and the White House website. More up-to-date results can also be found from a more recent visit to these sites.
We will use a run chart to plot the time in office to check for evidence of clusterings, mixtures, trends, or oscillations.