Two scatter diagrams.

In each scatter diagram, the horizontal axis shows Group, a categorical variable with three categories: "No RA, no oedema", "RA", and "RA + oedema". There are two columns of points for each group, one for Right arm and the other for Left arm. In every case, the two columns are similar and will be described together.

In the first scatter diagram, the vertical axis shows "Activity after two hours" and is numbered 0, 5, 10, 15, and 20.

For the No RA, no oedema group the points form a vertical column from Activity = 2 to Activity = 11. For the RA group the points form a vertical column from Activity = 2 to Activity = 17. For the RA + oedema group the points form a vertical column from Activity = 0 to Activity = 5. In each of these columns of points, there are more points near the bottom than near the top, where they are quite sparse.

In the second scatter diagram, the vertical axis shows "Square root activity" and is numbered 0, 1, 2, 3, 4, and 5.

For the No RA, no oedema group the points form a vertical column from Square root activity = 1 to Square root activity = 3.5. For the RA group the points form a vertical column from Square root activity = 1.3 to Square root activity = 4.5. For the RA + oedema group the points form a vertical column from Square root activity = 0.2 to Square root activity = 2.3. In each of these columns of points, there are more points near the bottom than near the top. However, this effect is not so great as in the first diagram. The distribution, though still skew, is less so.

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This page maintained by Martin Bland.

Last updated: 3 August, 2006.