This shows the V and Z points plotted on the test template, with extra lines added.

The template has two axes and two sloping lines. The horizontal axis is labeled V with a scale 0, 4, 8. The vertical axis is labeled Z and has scale minus 4, minus 2, 0, 2, 4, 6. A solid line runs from V = 0 and Z = 3.2 to V = 7 and Z = 6. The area above this line is labeled "Significant: experimental treatment better". A solid line runs from V = 0 and Z = minus 3.2 to V = 1 and Z = minus 1.8. The area below this line is labeled "Significant: experimental treatment worse". This line continues as a broken line from V = 1 and Z = minus 1.8 to V = 7 and Z = 6. The area below this broken part of the line is labeled "Not significant". Points are shown at V = 0.25 and Z = 0.57, V = 1.23 and Z = 2.09, V = 1.97 and Z = 2.89, V = 2.97 and Z = 4.71. The last point is just below the boundary line. Dotted lines have been added. One jagged dotted line starts at V = 0 and Z = 3.2, dips slightly then is horizontal to V = 0.25 and Z = 3.0, where it rises vertically to touch the upper boundary. It then dips slightly and is horizontal to V = 1.23, where it rises to meet the upper boundary again. It then dips slightly and is horizontal to V = 1.97, where it rises to meet the upper boundary again. It then dips slightly and is horizontal to V = 2.97, where it rises to meet the upper boundary again. The final point is on this vertical line. The dotted line continues, dipping slightly then rising gently to V = 4.8, Z = 4.2. A second dotted line starts at V = 0 and Z = minus 3.2, rises to V = 1.23, Z = minus 2.5, where it drops vertically to meet the lower boundary again. It then rises sharply to V = 1.97, Z = minus 1.2, where it drops vertically to meet the lower boundary again. It then rises to V = 2.97 and Z = 1.2, where it drops to meet the lower boundary again. The dotted line continues, rising to V = 4.8, Z = 4.2, where it meets the first dotted line. Each of these dotted lines has a saw-toothed effect, the verticals coinciding on the V scale with the plotted points.

Back to Some alternative trial designs.

This page maintained by Martin Bland.

Last updated: 20 July, 2009.