2022 Introduction to Statistics in Research Mitchell 2nd ed

I N T R O T O R E S E A R C H : D A T A V I S U A L I Z A T I O N & C O M M O N S T A T T E S T S

The first one , called “Bad Chart,” does not use frequencies - it uses the count. At first glance, you would assume that students are more likely to want to attend college less than 250 miles from home than parents. This is a bad chart, because the bar graph using counts will not take into account the difference in sample sizes at will lead the user to the wrong conclusion. Notice that 9,282 students took the survey and only 2,618 parents took the same survey.

Table 52: Chart based on counts - misleading

Now, let's look at a chart that used the frequencies. Remember, to arrive at frequencies, we took the count and divided it by the total. So for example, 2878 divided by 9282 gives us .31 (or 31% of students want to go to a school less than 250 miles from home.) But notice the parents - 47% of them want their child's school to be less than 250 miles from home!

Table 53: Chart based on frequencies, good chart

69