Assignment Preparation

This unit provides context for an upcoming assignment on histograms and descriptive statistics in Unit 3. Look ahead at the instructions and scoring guide for the Unit 3 assignment so that you have it in mind as you study the materials and complete the activities in this unit.

Software Installation

Make sure that IBM SPSS Statistics Standard GradPack is fully licensed, installed on your computer, and running properly. It is important that you have either the Standard or Premium version of SPSS that includes the full range of statistics. Proper software installation is required in order to complete your first SPSS data assignment in Unit 3.

Next, click grades.sav to download the file to your computer.

•Important: Do not use the original George and Mallery grades.sav file, as the course room grades.sav is modified for 7864.

You will use grades.sav throughout the course. The definition of variables in the grades.sav data set are found in Chapter 1 of your IBM SPSS Statistics Step by Step text. Understanding these variable definitions is necessary for interpreting SPSS output.

Next week, you will define values and scales of measurement for all variables in your grades.sav file.

Histograms and Descriptive Statistics

Your first IBM SPPS assignment includes two sections in which you will:

1. Create two histograms and provide interpretations.
2. Calculate measures of central tendency and dispersion and provide interpretations.

Key Details and Instructions

• Submit your assignment as a Word document.
• Begin your assignment by creating a properly formatted APA title page. Include a reference list at the end of the document if necessary. On page 2, begin Section 1.
• Write your report in narrative format, integrating your SPSS output charts and tables with your responses to the specific requirements listed for this assignment. (See the Copy/Export Output Instructions in the Resources area.)
• Label all tables and graphs in a manner consistent with APA style and formatting guidelines. Citations, if needed, should be included in the text as well as in a reference section at the end of the report.
• Refer to the IBM SPSS Step-By-Step Guide: Histograms and Descriptive Statistics (in the Resources area) for additional help in completing this assignment.

Section 1: Histograms and Visual Interpretation

Section 1 will include one histogram of total scores for all the males in the data set, and one histogram of total scores for all the females in the data set.

Using the total and gender variables in your grades.sav data set, create two histograms:

• A histogram for male students.
• A histogram for female students.

Copy the histogram output from SPSS and paste it into a Word document. Below the histograms in your Word document, provide an interpretation based on your visual inspection. Correctly use all of the following terms in your discussion:

• Skew.
• Kurtosis.
• Outlier.
• Symmetry.
• Modality.

Comment on any differences between males and females regarding their total scores. Analyze the strengths and limitations of visually interpreting histograms.

Section 2: Calculate and Interpret Measures of Central Tendency and Dispersion

Using the grades.sav file, compute descriptive statistics, including mean, standard deviation, skewness, and kurtosis for the following variables:

• id
• gender
• ethnicity
• gpa
• quiz3
• total

Copy the descriptives output from SPSS and paste it into your Word document. Below the descriptives output table in your Word document:

• Indicate which variables are meaningless to interpret in terms of mean, standard deviation, skewness, and kurtosis. Justify your decision.
• Next, indicate which variables are meaningful to interpret. Justify your decision.
• For the meaningful variables, do the following:
  • Specify any variables that are in the ideal range for both skewness and kurtosis.
  • Specify any variables that are acceptable but not excellent.
  • Specify any variables that are unacceptable.
  • Explain your decisions.
• For all meaningful variables, report and interpret the descriptive statistics (mean, standard deviation, skewness, and kurtosis).

Submit both sections of your assignment as an attached Word document.

Resources

Software Installation

Make sure that IBM SPSS Statistics Standard GradPack is fully licensed, installed on your computer, and running properly. It is important that you have either the Standard or Premium version of SPSS that includes the full range of statistics. Proper software installation is required in order to complete your first SPSS data assignment in Unit 3.

Next, click grades.sav to download the file to your computer.