6.2. Experimental Design http://www.ck12.org
- (a) Because students with lower pulses may react differently than students with higher pulses, we will block
by pulse rate. Place the students in order from lowest to highest pulse rate, then take them two at a time.
TABLE6.2:
Pair Number Students
1 6 , 1
2 11 , 7
3 9 , 10
4 3 , 4
5 2 , 8
6 12 , 5(b) The calculator would generate the following 6 random ones and twos.
the order in which the students appear in the table as their number, the students could be assigned by placing the
chosen student for each pair into treatment 1, and the remaining student to treatment 2:
Treatment 1(black ink) 6 , 11 , 9 , 3 , 8 , 5
Treatment 2(red ink) 1 , 7 , 10 , 4 , 2 , 12(c) It is possible that different students react to testing taking and other situations differently and it may not affect
their pulse directly. Some students might be better test takers than others. The level of mathematics ability or
previous success on the subject matter being tested could also affect the stress level. Perhaps amount of sleep, diet,
and amount of exercise may also be lurking variables.
(d) A repeated measures design would help control for individual differences in pulse rate. Each student would have
to take both a black ink and red ink test. A second test would have to be carefully designed that was similar to
the first, but with different color ink. If you just gave the students the same test twice, their stress level might be
significantly lower when they take it the second time.
- The population is children with epilepsy who have not responded to other traditional medications.
- We need assurances that the children were randomly assigned to the treatment and control groups.
- The treatment is starting on the high fat diet immediately, the control group is the group who started the
diet 3 months later. Notice in this case, researchers did not completely withhold the treatment from the
control group for ethical reasons. This treatment has already shown some effectiveness in non-clinical
trials. - We would conclude that the high fat diet is effective in treating seizures among children with epilepsy
who do not respond to traditional medication.
- We will need at least 6 blocks to impose the various treatments, which are: Organic fertilizer, 1 inch Chemical
fertilizer, 1 inch Organic fertilizer, 2 inches Chemical fertilizer, 2 inches Organic fertilizer, 4 inches Chemical
fertilizer, 4 inches Assign the plots numbers from 1 to 6.
1 2 3
4 5 6