JOI1287, Fall 2019 1 Assignment #1 Due on: JOI1287-0101 & 0103: October 8th JOI1287-0102: October 10th The purpose of the assignment is to demonstrate your understanding of the concepts and application of the course materials covered up to this point. This assignment consists of two sections. Both must be completed. Please note that some marks will be assigned to the organization and quality of your assignment. Part 1. Conceptual Problems 1. What is the difference between a parameter and a statistic? Provide an example of each. 2. Four scales of measurement were introduced in this course nominal, ordinal, interval and ratio. a. What additional information is obtained from measurements on an ordinal scale compared to measurements on a nominal scale? b. What additional information is obtained from measurements on an interval scale compared to measurements on an ordinal scale? c. What additional information is obtained from measurements on a ratio scale compared to measurements on an interval scale? 3. A researcher would like to evaluate the claim that large doses of vitamin C can help prevent the common cold. One group of participants is given a large dose of the vitamin (500 mg per day), and a second group is given a placebo (sugar pill). The researcher records the number of colds each individual experiences during the 3-month winter season. a. Identify the dependent variable for this study. b. What scale of measurement is used for the dependent variable? c. Identify the independent variable for this study. d. What scale of measurement is used for the independent variable? 4. Construct a frequency distribution for the following set of scores. Include columns for count and percentage in your table (you don’t need to include the cumulative percentage): Scores: 5, 7, 8, 4, 7, 9, 6, 6, 5, 3, 9, 6, 4, 7, 7, 8, 6, 7, 8, 5 5. A survey given to a sample of 200 college students contained questions about the following variables. For each variable, identify the kind of graph that should be used to display the distribution of scores. a. Size of T-shirt worn (S, M, L, XL) b. Gender (male/female) c. Grade point average for the previous semester d. Response time to a stimulus 6. What information is available about the data in a regular frequency distribution that is not available in a grouped frequency distribution? JOI1287, Fall 2019 2 7. Why is it necessary to have more than one method for measuring central tendency? 8. A sample of n=14 scores has a mean of M = 5. One person with a score of X = 10 is added to the sample. What is the value for the new sample mean? 9. Explain what measure of central tendency is best used to represent a skewed distribution? Why? 10. Can SS ever have a value less than zero? Explain your answer. 11. Explain what it means to say that the sample variance is an unbiased estimate of the population variance. 12. Describe what happens to the deviation scores and the standard deviation when a constant is added to every score in the distribution. 13. For a population with a standard deviation of σ = 10, a score of X=44, corresponds to z= – 0.50. What is the population mean? 14. On an exam with µ = 50 and σ = 8, find the z-score for each of the following X values: a. X=54 b. X=62 c. X=48 15. Find the X value corresponding to z=0.50 for each of the following distributions: a. µ = 50 and σ = 4 b. µ = 50 and σ = 8 JOI1287, Fall 2019 3 Part 2. Application of Concepts Using SPSS In this section you will use SPSS to complete all analyses. A description of the data can be found below. The data you will be using for this course can be found in the SPSS data file Sesame.sav. A description of the data can be found at the end of this document. Instructions: The following is a list of tasks you will need to complete in SPSS using the data provided: 1. Review the codebook provided (under Description of Data below) and the information in the Variable View of SPSS to determine if the assigned scale of measurement for each variable is accurate. Please make note of any changes you made as you will need to communicate those changes to me in your response to this section. 2. Use the codebook to assign values to variables, where appropriate. You will need to be in the Variable View of SPSS to complete this task. 3. Identify and produce appropriate descriptives for two continious and two categorical variables in the datafile. Please remember that your choice of descriptives depends on the measurement scale. Below are examples of some of the descriptives you can use with your data. o Frequencies o Measures of central tendency o Bar graphs o Histograms 4. Use the CROSSTABS command in SPSS to explore the relationships among the categorical variables in your data. You do not need to explore every single relationship but think of two that might be most meaningful or interesting. 5. Choose two categorical variables: (1) one with only two categories and (1) one with more than two categories. Use the SPLIT FILE command with each of the categorical variables one at a time and then run appropriate descriptives for two continuous variables. This means you will be running two separate sets of descriptive analyses for each of the categorical variables chosen. Please remember to take the SPLIT FILE OFF once you have completed this task. 6. As you review your output please make note of any interesting and/or unusual patterns in your data as you will need to communicate these to me in your response to this section. As a suggestion you may want to include and highlight at least 6 aspects of the data that were interesting or may need to be further explored. **As you work through this section of the assignment to each task some of the SPSS procedures completed may have been done through trial and error as you become familiar and comfortable with the program. However, once you are satisfied that you have successfully completed each task assigned please make sure that the syntax and output provided from SPSS matches these tasks only. In other words, please submit a clean SPSS syntax and output file. Deliverables: o Submit your assignment in one MS Word or PDF file to the “Assignment#1- Students’ Submission” folder on the Pepper website following the instructions provided there. JOI1287, Fall 2019 4 o Prior to uploading your file please include your name in the saved documents. For example, (JOI 1287-Assignment#1_Your Name.doc) as this will make it easier for me to track your assignments. o Your assignment should include: o Responses to questions from Chapters 1-5 in Part 1. Please be sure to include all calculations. o Written interpretation of the findings from descriptive analyses completed in Part 2, tasks 2-6. This may include (but is not limited to) meaningful/interesting/problematic observations or patterns in your data. Any ideas, speculations, and questions that you may have about your data. In other words, tell me a story about your data, pretend that I have no prior knowledge about your data and you want to report the results of your descriptive analyses in such a way that I can understand the nature of the variables. o SPSS output and syntax. (Your output should include syntax lines with comments, please copy/paste the relevant contents of this file and add to your interpretation). Description of Data: This data is part of a large data set that evaluated the impact of the first year of the Sesame Street television series. Sesame Street was concerned mainly with teaching preschool related skills to children in the 3-5 year age range, with special emphasis on reaching 4 year old disadvantaged children. The format of the show was designed to hold young children’s attention through action oriented, short duration presentations teaching specific preschool cognitive skills and some social skills. Each show was one hour and involved much repetition of concepts within and across shows. A main concern for the evaluation, which was carried out at Educational
Testing Service, was that it would permit generalization to the populations of children of most interest to the producers of the program (the Children’s Television Workshop). Five populations were of interest: 1. Three to five year old disadvantaged children from inner city areas in various parts of the country. 2. Four year old advantaged suburban children. 3. Advantaged rural children. 4. Disadvantaged rural children. 5. Disadvantaged Spanish speaking children. Children representative of these populations were sampled from five different sites in the United States. Both before and after viewing the series the children were tested on a variety of cognitive variables (variables 8 through 19 in the data set), including knowledge of body parts, knowledge about letters, knowledge about numbers, etc. The variables in the dataset are listed and described below. Variable Name Description 1.ID Subject identification number 2.SITE Five different sampling sites coded as 1, 2,3, 4, or 5 3. SEX Male -1; Female – 2 JOI1287, Fall 2019 5 Variable Name Description 4. AGE Recorded in months 5. VIEWCAT Viewing categories coded as 1 if children rarely watched the show to a 4 if the children watched the show on average of more than 5 times a week 6. SETTING Setting in which Sesame Street was viewed, coded as 1 for home and 2 for school 7. VIEWINC A treatment condition in which some children were encouraged to view Sesame Street (coded as 1) and others were not (coded as 2) 8. PREBODY Pretest on knowledge about body parts (maximum score of 32) -naming and functions of body parts 9. PRELET Pretest of knowledge about letters (maximum score of 58) – including recognizing letters, naming capital letters, matching letters in words 10. PREFORM Pretest on knowledge about forms (maximum score of 20) – recognizing and naming forms 11. PRENUMB Pretest on knowledge about numbers (maximum score of 54) -recognizing and naming numbers, counting, addition, and subtraction 12. PRERELAT Pretest on knowledge of relational terms (maximum score of 17) – amount, size, and position relationship 13. PRECLASF Pretest on knowledge of classification skills (maximum score 24) – classifying by size, form, number, and function 14. POSTBODY Posttest on knowledge about body parts 15. POSTLET Posttest of knowledge about letters 16. POSTFORM Posttest on knowledge about forms 17. POSTNUMB Posttest on knowledge about numbers 18. POSTRELAT Posttest on knowledge of relational terms 19. POSTCLASF Posttest on knowledge of classification skills 20. PEABODY Mental age scores obtained from administration of the Peabody Picture Vocabulary Test (PPVT) as a pretest measure of vocabulary maturity JOI1287, Fall 2019 6 Example for formatting 1. Crosstabulations Gender and Setting CROSSTABS /TABLES=setting BY sex /FORMAT=AVALUE TABLES /CELLS=COUNT ROW /COUNT ROUND CELL. Setting in which Sesame Street was viewed * Sex Crosstabulation Sex Total male female Setting in which Sesame Street was viewed Home Count 71 72 143 % within Setting in which Sesame Street was viewed 49.7% 50.3% 100.0% School Count 44 53 97 % within Setting in which Sesame Street was viewed 45.4% 54.6% 100.0% Total Count 115 125 240 % within Setting in which Sesame Street was viewed 47.9% 52.1% 100.0% You should add some blurbs after each output and explain your interpretation of the findings that are noticeable. Relevant SPSS Output
