This chapter focuses on different research designs in experimental sociology. Most definitions of what constitutes an experiment converge on the idea that the experimenter "control" the phenomenon under investigation, thereby setting the conditions under which the phenomenon is observed and analyzed. Typically, the researcher exerts experimental control by creating two situations that are virtually identical, except for one element that the researcher introduces or manipulates in only one of the situations. The purpose of this exercise is to observe the effects of such manipulation by comparing it with the outcomes of the situation in which the manipulation is absent. One way to look at how the implementation of this rather straightforward exercise produces a variety of designs is by focusing on the relationship that experimental design bears with the theory that inspires it. Therefore, we begin this chapter with a discussion of the relationship between theory and experimental design before turning to a description of the most important features of various types of designs. The chapter closes with a short overview of experiments in different settings such as laboratory, field, and multifactorial survey experiments.

Chapter 2 sets the stage for the rest of the book by introducing the major components of intervention research studies on grammatical phenomena and by providing a brief overview of major approaches to grammar teaching. The first half of Chapter 2 lays out the timeline and components of an intervention research study, including the pretests and posttests; considers the common types of intervention study design (experimental vs. quasi-experimental, comparison group vs. control group design); and discusses the advantages and disadvantages of placing an intervention study in the lab vs. in the classroom. The second half of the chapter reviews major approaches to grammar teaching, with a primary focus on those approaches commonly used in interventions studies on grammatical phenomena, including focus on form approaches and Input Processing instruction.