Abstract
This chapter introduces the reader to the way that social scientists think about the world around them. It focuses on how communication researchers employ and use numbers as assigned values to variables and how these variables influence each other in relation to communication outcomes. The chapter begins by looking at six unscientific sources of knowledge and follows that with five ways that science adds to our body of knowledge about communication and communication effects. It then demonstrates how quantitative communication tests its theoretical predications. Finally, the chapter discusses the concept of variance and its importance in statistical analysis for quantitative research.