number of people to complete a loneliness scale as well as a depression inven-
tory. If loneliness and depression are related, we would expect people whoscore high on loneliness to also score high on depression. Similarly, those
who score low on loneliness should score low on depression.
Figure 2.3 presents three possible outcomes for this study. Each point on
the figure represents one participant ’s scores on both scales. The first outcome
indicates that a person ’s score on one scale is a fairly good predictor of that
person ’s score on the other scale. In this case, if we know someone is high
on loneliness, we know that person is probably going to score high on depres-
sion as well. The second outcome indicates little or no relationship between
the measures. Knowing a person ’s score on one scale tells us nothing about
what the other score will be. The third outcome, like the first, indicates that
knowing a person’ s loneliness score will help predict the depression score,
but not in the way we might have anticipated. Here, a high score on one mea-
sure predicts a low score on the other.
After conducting the appropriate statistical test, we can reduce the data
from our study to a single number, the correlation coefficient. This number
can range from 1.00 to /C01.00. Returning to the figure, the first outcome in-
dicates a fairly strong relationship between loneliness and depression. The
correlation coefficient for this figure might be .60. Because a high score on
one measure indicates a high score on the other measure, this is a positive
correlation. For the second outcome, the correlation coefficient is close to
.00, indicating no relationship between the measures. The third outcomemight yield a correlation of /C0.60, also a fairly strong relationship between
the variables. This last outcome is referred to as a negative correlation,
but this does not mean it is less important than a positive correlation ofthe same magnitude. For example, if we had compared scores on a
loneliness scale with scores on a sociability measure, we probably would
have anticipated that a high score on one test would predict a low score onthe other.Depression
Loneliness1010203040
20 30 40
Depression
Loneliness1010203040
20 30 40
Depression
Loneliness10 00010203040
20 30 40
FIGURE 2.3 Three Possible Relations Between Loneliness and Depression32 CHAPTER 2 Personality Research Methods