Collect data from exactly 19 people in your first group, and exactly 19 people in your second group. (So if you are investigating sex differences, for example, collect data from exactly 19 women and 19 men). Ask each participant your question or get your measurement. Please try and keep the subject responses confidential (you will be more likely to get honest and accurate answers—this also protects the subject). Record your data in a table that includes the participants’ group and their response. **When completing this report, please watch for differences between the project guidelines, the versions of SPSS, and the instructions in the Homework Packet** 2 Complete the following:
1. Write an introduction explaining the following: (3 points) a) how and where you collected your data b) what you controlled for and could not control for as a researcher (That is, explain what other influences or independent variables that you could/did not control that may have resulted in your data set not accurately representing your groups. [That is (for example), what kinds of factors can control how much someone studies each week outside of their gender? Were those factors that you could control or did not have control over while collecting your data?] c) why you are studying these particular variables d) what you expect to find, and WHY! e) **be sure to add a copy of your data**
2. What is your independent variable? What is your dependent variable? For each variable identify the following: a) type of data: categorical or measurement (2 points) b) scale of measurement: nominal, ordinal, interval, ratio c) Is the dependent variable discrete or continuous?
3. Using SPSS, construct a frequency distribution for each group. Include output here. Discuss your findings [For example, what scores did most of your participants get; were the scores grouped together, or all spread out; etc…]. (1 point)
4. Using SPSS, construct a histogram for each group. Include output here. Be sure the axes are clearly labeled. Based on the graphs, describe the shape and modality of each distribution. (Hint: You will need to split your file in SPSS) [For example, are your distributions normal? This could impact how you answer question 5c] (1 point)
5. Using SPSS calculate the mean, median, and mode for each group. Include your output. Based on your findings, answer the following: (2 points) a) What is the average score in each distribution? b) What score corresponds to the 50th percentile in each distribution? c) Which measure of central tendency is the better one to report for each of your distributions and explain why?
6. Using SPSS, calculate the range, variance, and standard deviation for each distribution. Include your output. (1 point) a) Interpret the standard deviation for each group. b) Do you have much variability in your data? c) Which distribution has more variability?
7. Using SPSS create a z-distribution for each group. Include/provide your output. (3 points) a) What raw score best corresponds to the top 20% for each distribution? b) What raw score best corresponds to the 30th percentile for each distribution? (Hint: Look up the corresponding z-scores in your tables and find which values in each of your distributions best (is closest to) the z-score you looked up) [Using Howell, find the z-scores at the 30th percentile, and the top 20% or 80th percentile. Now look at your z-distribution for each of your 2 groups and find the zscores that are closest….what are the corresponding raw scores?]