ASSIGNMENT TWO
INTERPRETING STATISTICS

Step four describes the differences research question and its associated hypothesis that are explored by gathering, analyzing and interpreting the data using the t-test.

Resarch Question .... Is there a difference between gender and weight loss?

Research Setting .... You are studying the same group of 50 people in the exercise class. The class has a fairly even distribution of genders and ages from 20 to 60. All the people have participated in the class for 30 weeks. You measured their weight at the beginning of the program and at the end of 30 weeks. You wonder if gender is associated with weight loss. You hypothesize that the women will have lost, on the average, more weight than the men.

Study the part of your analysis page dealing with t-tests, then answer the questions below. Your answers to these questions form your interpretation and conclusions.

  1. Describe your subjective impressions from the means and standard deviations for men and women, and from the bar chart and error bars. The term, error bars, refers to the vertical lines that extend above and below the top of the bars on the chart.  The error bars show the spread of scores around the middle of the distribution for each group. The group with the longer bars has the greater variability; e.g., range of scores.
  2. What is the t-value and its associated probability? What standard are you using to decide if it is significant? Does it indicate a significant difference between the means for women vs. men on weight loss? If the t-test is significant which group lost the most weight? Further information about the interpretation of t-tests can be found in the The Research Methods Knowledge Base by William Trochim and in Biostatistics for the Clinician by Oser,  Johnson, and Abedor. The exact probability of the t-value is given on your analysis page. Compare this probability to your standard to see if the t-test indicates a significant difference between the means.
  3. What is your conclusion about the hypothesis? Is it supported or not? Do you feel the study has fully answered the research question?

Think through your answers to these questions. Step 5 will provide some examples to explore your understanding, and step 6 contains directions on how to write your report and submit it to your instructor for credit.