Homework Chapter 6
Assignment:
Objective: Apply concepts Repeated Measures Design
- A researcher is contemplating various ways to design their study examining the effects of irrigation on crop yield. The first possible design would be to take a sample of yields from plots with a standard irrigation system and compare them to the known yield from plots without irrigation in the same region. Another would be to sample irrigated and non-irrigation crop yields from various regions and compare them, ensuring the plots are matched on the variable of region. A final option would be to sample crop yields from the same plots first before and then after installation of a standard irrigation system and compare the yields prior to irrigation to those following irrigation. The research design that would best represent repeated measures design is ______________.
Objective: Apply techniques Conducting a Dependent Means t-test
- A researcher predicts crop yields sampled from the same plots first before and then after installation of a standard irrigation system will differ. The scores for the research samples before and after irrigation are presented in the table below, in units (bushels per hectare; N=28). Conduct a hypothesis test of the researcher’s prediction with significance level .10. The populations should be defined as ______________.
| Plot | Before irrigation | After irrigation |
| 1 | 163 | 208 |
| 2 | 131 | 198 |
| 3 | 160 | 208 |
| 4 | 183 | 198 |
| 5 | 168 | 186 |
| 6 | 135 | 177 |
| 7 | 179 | 173 |
| 8 | 143 | 203 |
| 9 | 161 | 203 |
| 10 | 154 | 192 |
| 11 | 162 | 186 |
| 12 | 163 | 185 |
| 13 | 166 | 176 |
| 14 | 181 | 184 |
| 15 | 132 | 199 |
| 16 | 149 | 197 |
| 17 | 169 | 199 |
| 18 | 148 | 202 |
| 19 | 169 | 188 |
| 20 | 158 | 200 |
| 21 | 143 | 201 |
| 22 | 150 | 191 |
| 23 | 178 | 194 |
| 24 | 147 | 185 |
| 25 | 170 | 202 |
| 26 | 171 | 178 |
| 27 | 169 | 212 |
| 28 | 180 | 180 |
- For the research scenario described in problem 2, the hypotheses should be defined as ______________.
- For the research scenario described in problem 2, the characteristics of the comparison distribution should be defined as ______________.
- For the research scenario described in problem 2, the cutoff t score should be ______________.
- For the research scenario described in problem 2, the calculated t-test result should be ______________.
- For the research scenario described in problem 2, the hypothesis test decision should be ______________.
- For the research scenario described in problem 2, the p-value associated with the t-test result is _____________.
- For the research scenario described in problem 2, the conclusion as written in a published results section could be ______________.
Objective: Apply concepts Decision Tree
- The dependent means t-test is appropriate to use when ______________.
