Everyone requires food to survive. For those who have had psychology, this was mentioned as being at the very base (biological/psychological needs) of Maslow's Hierarchy of Needs. For those of you who haven't had psychology, try going for any length of time without food and you will see how important it is.
Although people are eating out more, the average American still ate 917 meals at home in 19991.
Some people may eat out every meal but many of us aren't that wealthy and have to buy our own food at the grocery store. A naturally arising question is "Is one grocery store cheaper than another?" That's the question we're going to set out to answer this semester. Hopefully we'll have some fun and learn something about statistics along the way.
This is a semester long project involving many of the aspects of Statistics. It will involve planning an experiment, collecting data, describing the data, analyzing the data, and making inferences from the data. It can also serve as an example for the project that students will have to perform the second half of the semester.
The class will be divided into groups of approximately 4 students each depending on the number of people in the class. Each group will be assigned one grocery store. The different grocery stores in town that we'll be choosing from are Aldi's, Cub Foods, Kroger's, Schnucks, Eagles, and WalMart.
The groups will be assigned by factors including store preference, available times, and computer skills. Although there will be some class time given to work on projects, there may be some instances where you need to work together outside of class. Most of the time, the work can be accomplished either right before or right after the class.
The assignment of groups will occur at the beginning of the semester, either the first or second day of class.
Periodically, information will be turned in for a grade. All assignments submitted for a grade should have the name of the grocery store and the name of all the students in the group at the top of the paper. All information submitted to the instructor is to be printed. SPSS output should be cleaned up and annotated.
Parts of the project will be due at different times. Due dates and point values are available at the end of this document.
Sample Grocery List
Your first assignment is to come up with a typical grocery list for your family. The grocery list must contain at least 20 items and at least three items from each of the major categories, although you are encouraged to make it as realistic and lengthy as possible. If you don't do the grocery shopping in your family, then talk to the person who does for an idea of what to put on the list. These will be compiled into a master list that will be used to compare grocery prices.
Assign each item on your grocery list into one of the following categories:
GM/HBC (General Merchandise / Health & Beauty Care) (9.66%)
The percent values following the major categories represent the percent of 2000 sales that category accounted for2.
You may include name brands if you shop for name brands.
Once everyone returns their list, we will compile it into a master list of items to gather prices for.
Once the master list is compiled, the groups will go to their grocery stores and find the prices for the items on the list. Follow these guidelines for collecting data.
All stores will be visited during the same week.
After the data has been collected, it will be entered into SPSS.
See the data definition section for more information on how the file is composed.
Each group will save their information into a file for just that group. Save the file on the acad1 server in the \stats\01\food\ directory. Use the name of your store as the filename. You can specify the complete filename as \\acad1\stats\01\food\cubs.sav or \\acad1\stats\01\food\krogers.sav (SPSS data files have the extension .sav, you don't need to enter this). Do NOT use spaces, apostrophes, capitals, or other special characters in your filename.
If you were unable to collect a price for a certain grocery item, be sure to let the instructor know. When we compare prices, it is important that we are comparing the same things at each store, so some items may have to be eliminated from the final list.
Once the data for each group has been entered into SPSS, we will combine it into one master file for the entire class to use. That file will be called food.sav and will be in the \\acad1\stats\01\food\ directory.
Download a blank Excel file to enter the data into.
Use the data for your store only to answer the questions in this phase. The SPSS commands necessary to complete the task are in italics after each instruction.
You will probably want to save your output as you go along so that you don't accidentally lose anything if the computer crashes.
Use the combined file for this phase of the project. This portion of the project uses information from chapters 7 and 8. Each group's results will be different from the other groups.
The output from SPSS should be cleaned up and annotated. Be sure to add the store name and the group members to the top of the output.
This portion of the project requires information from chapters 10 and 11 and so it will be due at the end of the semester. You will feel frustrated and pressured that there is little time to complete the task, but there is little that can be done since we won't have covered the necessary material until the end. The report given by each group will be the same for this portion.
As a group, comment on the entire project. As a minimum, address questions like
This should be typed and only one document submitted per group.
As an individual, evaluate each member of your group including yourself. Comment on how much they contributed to the group. Did they show up for all the meetings, did they participate when they showed up, did they pull their weight or did they not do anything.
In addition to a paragraph describing each person, assign them a score between 0 and 10 points for their effort in the group. Remember you are evaluating yourself, also.
The score that you receive for this part of the project will be the mean scores given to you by each person in your group. All evaluations should be on a single sheet of paper that may be typed or handwritten. This is an individual assignment, not a group project.
Some of the information will be collected and entered by the students into SPSS.
|Jun 10||Phase 1 - Grocery List Due|
|Jun 17-21||Phase 2 - Collect Data from Stores|
|Jun 26||Phase 2 - Data entered|
|Jul 3||Phase 3 - Descriptive Statistics Due|
|Jul 12||Phase 4a - Inferential Statistics, part 1, due|
|Jul 23||Phase 5 - Evaluations due|
|Jul 24||Phase 4b - Inferential Statistics, part 2, due|