MB 313
Homework 1

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This is an exercise in visually examining data. We will use the dataset describing students’ attitudes towards the environment and the paranormal (dataset = site89Para.sav) to visualize and describe the data. Here is the codebook describing the data, and here is the questionnaire. Write up your results in paragraphs answering each question. You do not need to show the printouts for Question 1, but please cut and paste the plots for questions 2 and 3. The homework should be typed and double spaced. It is due October 15.

  1. First, let’s look at the paranormal variables. What is the composition of the dataset in terms of paranormal attitudes (Para14 to 26)? You can use analyze>descriptive statistics> frequencies to answer this question. Click on Statistics=mean and Charts= bar charts. Which paranormal beliefs do more people believe in?

 

  1. Next, let’s combine paranormal attitudes into an index. First, we need to add together Para14 to Para26.  In order to do this you will need to go to the pull down menus at the top of the screen and go to Transform>Compute variables. For the “Target variable” type in ParaIndex. Click on “Type and label” below the type in box and then give the index a name such as Paranormal Index. Then under the compute box click on Para14 to Para26 with addition signs in between variables to make a simple additive scale. Now we want to plot this index as a histogram to see how the variable is distributed. If you are using SPSS 16.0, you can go to Graphs>Legacy Dialogs>Interactive>Histogram.  Drag the variable "ParaIndex" into the horizontal box. Then click on the Histogram tab at the top of the window and click on normal curve. Click on "OK", and then look at the result in the output. Let us compare your class to last year by doing a boxplot of the two classes side by side. (Graphs>Legacy Dialogs>Boxplot). A window opens up and "Simple" should be highlighted. Click on "Define" at the bottom of this window. In the next window click on "ParaIndex" for the variable and "siteid" for the category axis, and click on "OK". A boxplot shows the median with a box surrounding it showing the middle 50% of the data, with lines drawn from both ends of the box that represent about 95% of the data, and anyone outside of the lines being an outlier and shown as a small circle. How do the two classes compare? (Remember that a higher value means more belief in the paranormal.)

 

3.  Now let’s look at a continuous variable by groups or categories of another variable. Let us test the hypothesis that with age comes wisdom. In this case, let’s boxplot ParaIndex by class to see if seniors score lower on the ParaIndex as compared to others.  Look at two boxplots side by side to see how the classes vary on the ParaIndex. (Graphs>Legacy Dialogues > Boxplot), check “Summaries are for groups of cases” in the boxplot window, Variable= ParaIndex, category axis = Class). You can also look at three histograms at once. Go to Graphs>Legacy Dialogs >Histogram, Variable = ParaIndex, Rows = Class. Which class is most likely to believe in paranormal phenomena?

This page last modified on 10/5/09