Week 3 --PPOL 505 Exercise 2

Chapter 4: Problem 3

1. For problem three in chapter four, a teacher wants to display her students number of responses for each day of the week. And she wants to do that with a bar chart. Since she hasn't taken a stats class, she comes to you for help. You first enter her data into SPSS and the results look like this-- When you look at your data set, you'll see that it actually has the wrong level of measurement. Notice that there's a little Venn diagram at the top of each column, which indicates that your data has been entered as nominal. That would be correct if you were noting which day of the week a student participated, but since you're noting how often a given student participated, the correct level of measurement is a scale. Go ahead and change that. Watch how I do that. Under variable view, under measure, you just want to click each one and turn it into a scale. You can also cut and paste these, and I can show you that in another video. Once you have them changed, go back to data view, and you'll see that at the top it has changed in two little rulers. The next question is, how do I get SPSS to display the average score per day rather the total number of individual scores, which might look like a mess, and it's why this question is a toughie. To do that we go under graphs, and you'll see that you have two options, you can do a Chart Builder or a Legacy Dialog. For this question we want to use the Legacy Dialog. We go to Bar and when we click that, there are two questions-- one, what type of bar chart? We want a simple one. And then, how do you want the data in their area displayed? Do we want to summarize for the groups? We really don't. We want summary of separate variables where each day of the week is a variable. We click on Define and then here you'll see every day of the week. You want to bring that over and you see your bar charts are going to represent the mean for every day of the week. As a good habit you want to make sure you title it, I called it "Students' Engagement During Group Discussion." The second one is by day of week. We hit Continue, and then when we hit OK, you're going to see your output pop up. And here is our bar chart-- every day of the week showing the average student engagement. And this is how you answer problem 3 in chapter 4. Good luck.

2. Identify whether these distributions are negatively skewed, positively skewed, or not skewed at all and explain why you describe them that way.

a. This talented group of athletes scored very high on the vertical jump task.

b. On this incredibly crummy test, everyone received the same score.

c. On the most difficult spelling test of the year, the third graders wept as the scores were delivered and then their parents complained.

3. Use the data available as  Chapter 4  Data Set 3 on pie preference to create a pie chart ☺ using SPSS.

4. For each of the following, indicate whether you would use a pie, line, or bar chart and why.

a. The proportion of freshmen, sophomores, juniors, and seniors in a particular university

b. Change in temperature over a 24-hour period

c. Number of applicants for four different jobs

d. Percentage of test takers who passed

e. Number of people in each of 10 categories

5. Provide an example of when you might use each of the following types of charts. For example, you would use a pie chart to show the proportion of children who receive a reduced-price lunch that are in Grades 1 through 6. When you are done, draw the fictitious chart by hand.

a. Line

b. Bar

c. Scatter/dot (extra credit)

6. Go to the library or online and find a journal article in your area of interest that contains empirical data but does not contain any visual representation of them. Use the data to create a chart. Be sure to specify what type of chart you are creating and why you chose the one you did. You can create the chart manually or using SPSS or Excel.

7. Create the worst-looking chart that you can, crowded with chart and font junk. Nothing makes as lasting an impression as a bad example.

8. And, finally, what is the purpose of a chart or graph?