EXAMPLE OF CLAIM AND EVIDENCE STATEMENT
BASED ON BOUNCE INVESTIGATION AND
PROCESS USED IN ADMIN BREAKFAST 2/4/2015
Hypothesis:
The basketball will bounce higher on the basketball court than on the carpet or grass
because the ball will lose some of its energy when compressing the grass or carpet. This
energy loss will not occur on the hardwood surface.
CLAIM:
The data supported the hypothesis.
MEANS:
What I see is… the mean bounce height is highest on the basketball court and lowest on
the grass. The carpet bounce height is intermediate between the grass and the basketball
court. Further, the mean bounce heights on each surface are not close—the means are far
apart.
VARIABILITY (scatter, range):
What I see is… the raw bounce data (not averaged) drawn as dots on the bar graph are
close to the mean for that surface. Further, the raw bounce data on different surfaces
don’t overlap, meaning that all the carpet trials are greater than all the grass trials, and all
the basketball court trials are greater than all the carpet trials. Another way to say this is
the ranges at each level of the IV are small (between 3 and 4), and don’t overlap. The
small amount of scatter in the data, and the fact that the ranges don’t overlap, tells me
that the differences between bounce heights on different surfaces are real (not due to
chance).
VARIABILITY (visualizing the MAD):
What I see is… the MAD values (showing average distance of raw data away from their
mean) are small. Also, when the MADs are drawn on the bar graph, they do not overlap.
What this means is… the bounce heights are very different depending on which surface is
used—so different that there is little or no overlap between trials on different surfaces.
VARIABILITY (MAD ratio):
The ratio of the difference in the means to the MAD (MAD ratio) is greater than 1;
therefore, I am confident that the change in DV (bounce height on different surfaces) is
real and my hypothesis is supported.