Page 51 - Essencials of Sociology

24 CHAPTER 1 The Sociological Perspective

TABLE 1.3 Three Ways to Measure “Average”

The Mean The Median The Mode

The term average seems clear enough. As To compute the second average, the The third measure of average, the mode, is
you learned in grade school, to find the median, first arrange the cases in simply the cases that occur the most often.
average you add a group of numbers order—either from the highest to the In this instance the mode is 57, which is way
and then divide the total by the number of lowest or the lowest to the highest. That off the mark.
cases that you added. Assume that the arrangement will produce the following
following numbers represent men distribution.
convicted of battering their wives.
EXAMPLE EXAMPLE EXAMPLE
321 57 1,795 57
229 57 321 57
57 136 289 136
289 229 or 229 229
136 289 136 289
57 321 57 321
1,795 1,795 57 1,795
The total is 2,884. Divided by 7 (the number Then look for the middle case, the one that Because the mode is often deceptive, and
of cases), the average is 412. Sociologists call falls halfway between the top and the bot- only by chance comes close to either of the
this form of average the mean. tom. That number is 229, for three numbers other two averages, sociologists seldom use
The mean can be deceptive because it is are lower and three numbers are higher. it. In addition, not every distribution of cases
strongly influenced by extreme scores, either When there is an even numbers of cases, the has a mode. And if two or more numbers
low or high. Note that six of the seven cases median is the halfway mark between the two appear with the same frequency, you can
are less than the mean. middle cases. have more than one mode.
Two other ways to compute averages are
the median and the mode.

© Robert Weber/The New Yorker Collection/www.cartoonbank.com
individuals a series of questions. Before you begin your research, however, you must deal
with practical matters that face all researchers. Let’s look at these issues.
Selecting a Sample. Ideally, you might want to learn about all wives in the world,
but obviously you don’t have enough resources to do this. You will have to narrow your
population, the target group that you are going to study.
Let’s assume that your resources (money, assistants, time) allow you to investigate
spouse abuse only among the students on your campus. Let’s also assume that your col-
lege enrollment is large, so you won’t be able to survey all the married women who are
enrolled. Now you must select a sample, individuals from among your target popula-
tion. Not all samples are equal. For example, married women enrolled in introductory
sociology and engineering courses might have quite different experiences. If so, survey-
ing just one or the other would produce skewed results.
Remember that your goal is to get findings that apply to your entire school. For
this, you need a sample that represents the students. How can you get a representative
sample?
To attain their goal of objectivity and The best way is to use a random sample. This does not mean that you stand on some
accuracy in their research, sociologists
must put away their personal opinions. campus corner and ask questions of any woman who happens to walk by. In a ran-
dom sample, everyone in your population (the target group) has the same chance of being
included in the study. In this case, because your population is every married woman
population a target group to be enrolled in your college, all married women—whether first-year or graduate students,
studied
full- or part-time—must have the same chance of being included in your sample.
survey the collection of data by How can you get a random sample? First, you need a list of all the married women
having people answer a series of enrolled in your college. Then you assign a number to each name on the list. Using a
questions
table of random numbers, you then determine which of these women will become part