ABSTRACT
This chapter describes the statistical and graphical approaches to summarizing measurements on a variable and discuss how to quantify the direction and strength of the relationship between two quantitative variables. A histogram is a handy way of visually representing the distribution of quantitative measurements. A histogram visually depicts frequency information by representing frequency with bars of different heights. The center of a distribution, typically described with the arithmetic mean, is an important descriptive statistic. The questions that communication researchers ask and the theories and hypotheses we test are often framed in terms of comparisons. A health communication researcher might ask whether a school-based intervention to increase adolescent awareness of safe sexual practices increases the students’ knowledge about sexually transmitted diseases and lowers the likelihood of engaging in risky sexual behavior. The correlation coefficient also gets its own symbol because it is so commonly used in research and statistical theory.
