Problem Set 1
A study was carried out to investigate problem solving by fifth-grade students. Thirty students were randomly assigned to one of three groups: (i) a direct problem-solving instruction method A1; (ii) a general introduction to problem solving, A2; or (iii) a control condition, C (study time with no instruction). The thirty students were administered a set of problems to solve at the conclusion of the learning experiment. Their results are provided below.
A1 A2 C
7 2 3
6 3 3
4 2 4
7 5 4
8 3 2
4 5 2
5 3 4
6 4 3
7 4 2
7 2 3
Carry out the appropriate regression analysis to compare treatment groups A1 and A2 to the control group, C.
What is the R2? Record your answer on the Answer Sheet
Copy and paste the regression summary table to the Answer Sheet
Write out the regression equation on the Answer Sheet
Assuming =0.05, were there significant effects due to either treatment, A1 or A2, relative to the control group C? Record your response on the Answer Sheet and include any relevant results from the regression analysis that support your conclusions. Note that there are two relevant null hypotheses: H_0: μ(A_1 )=μ_C and H_0: μ(A_2 )=μ_C.
What is the overall F ratio and what does it mean?
Problem Set 2
A study was carried out to evaluate two popular weight loss programs: Weight Watchers® and Noom®. Sixteen “motivated” subjects were randomly assigned to either the Weight Watchers or Noom program (eight per group). In addition, eight other participants were randomly selected to engage in “self-dieting” (i.e., no participation in any weight-loss). The 24 total participants were evaluated at three, six and nine months. Their weight loss during each three-month period was recorded and is shown below (positive numbers indicate weight loss, not gain).
2.1 Which type of analysis is best suited to evaluate the effectiveness of the three weight-loss “treatments”? (Record your answer on the Answer Sheet)
2.2 Run the appropriate analysis. Copy and paste the appropriate SPSS analysis summary table(s) to the Answer Sheet. (Note: there may be more than one appropriate summary table for this analysis).
2.3 Is there any statistically significant difference between the three weight-loss methods? Provide a brief (100 words or less) description of those findings on the Answer Sheet, including any relevant statistical results from your analysis.
2.4 Is there any statistically significant difference between the three time points? Provide a brief (100 words or less) description of those findings on the Answer Sheet, including any relevant statistical results from your analysis.
2.5 Is there any statistically significant interaction between the weight-loss method at the three time points? Provide a brief (100 words or less) description of those findings on the Answer Sheet, including any relevant statistical results from your analysis.
Problem Set 3
Thirty volunteer subjects participating in a hospital-based, outpatient obesity treatment program were randomly selected to participate in this study of body-fat reduction. There were fifteen women and fifteen men in the study. The dependent variable was the percentage of body fat lost as measured by bioelectrical impedance analysis (BIA) after 12 weeks of therapy. The three independent variables included hydrostatic measures (HYDRO) of the percentage of body fat (amount of body fat in water) taken at the beginning of the study, the patients’ age, and gender.
Women Men
BIA HYDRO Age BIA HYDRO Age
35 28 30 22 23 22
39 46 25 44 57 13
29 18 51 46 48 16
30 32 43 44 32 29
17 32 33 36 21 31
19 18 35 21 19 34
37 34 43 37 25 44
33 31 40 22 23 49
33 51 26 28 29 37
37 39 42 45 35 13
31 24 36 19 24 33
21 30 42 26 21 43
33 37 17 22 36 40
44 45 27 66 53 32
27 31 33 37 30 57
3.1 Run the appropriate regression analysis to predict BIA from the three independent variables. Your regression analysis should compare the women and men relative to the grand mean on the dependent variable. Copy and paste the regression summary table to the Answer Sheet in the space provided.
3.2 Do the three predictors significantly predict BIA? Summarize your findings on the Answer Sheet in 50 words or less.
3.3 What was the adjusted R2? Record your answer on the Answer Sheet.
3.4. Write out the regression equation on the Answer Sheet.
3.5 Were the coefficients all significant? Summarize the implications of those findings in 100 words or less on the Answer Sheet.
Problem Set 4
Pain assessment and management in nursing is predicated on the assumption that nurses and nursing assistants need to provide high-quality care for patients experiencing pain—especially since they tend to tend to spend more time with patients than other health team members. Nurses and nursing assistants are therefore very likely to routinely recognize pain symptoms, evaluate patient claims or self-evaluations, and assess other relevant cues. Experience is often assumed to account for improvement of cue-recognition skills among nursing professionals.
Three types of nursing professionals were randomly selected to participate in this study: (i) nursing assistants (NA); (ii) licensed vocational nurses (LVN, also known as licensed practical nurses); and (iii) registered nurses (RNs). The selection process further included two levels of experience within each of the three groups: (a) entry level individuals with three months of experience or less and (b) experienced nurses with five to ten years of clinical experience. There were n=10 nurses or nursing assistants in each of the design “cells” as shown below.
A cue-recognition test consisting of pain management scenarios with short videos was presented to each of 60 participants. The scores shown in the above table represent the number of cues correctly identified by each participant.
4.1 What are the three relevant hypotheses for this study? Described your hypotheses in 50 words or less on the answer sheet.
4.2 Run the appropriate analysis. Copy and paste the relevant analysis summary table to the Answer Sheet.
4.3 Was there an effect for experience, independent of the type of nursing program? Summarize that finding and your conclusions on the Answer Sheet in 50 words or less.
4.4 Was there an effect for the type of nursing program (NA, LVN or RN)? Summarize that finding and your conclusions on the Answer Sheet in 50 words or less.
4.5 Was there any type of association or interaction between experience and the type of nursing program? Summarize that finding and your conclusions on the Answer Sheet in 50 words or less.