Formalizing Ideas Into Research Hypotheses

(Research Hypothesis) Formalizing Ideas Into   Research Hypotheses

As you conduct your literature search, you will want to pay close attention to the organizing principles that form the basis of behavioral research. These principles include laws, theories, and research hypotheses. As we will see in the next sections, once you have read a great deal about your topic area, you will begin to develop more specifi c ideas about what you want to study, and you will be ready to begin formalizing your interests into a specifi c research hypothesis that you will test. 

Laws

Principles that are so general as to apply to all situations are known as laws. There are well-known laws in the physical sciences, such as the law of gravity and the laws of thermodynamics, but there currently are very few universally accepted laws within the behavioral sciences. This is partly because behavioral science research has not progressed as far as that in the natural sciences and partly because it is more difficult to specify laws of social behavior. In any case, because laws are such general principles and are considered so only because their validity has already been well established, they are themselves rarely directly subjected to scientific test. 

Theories

The next step down from laws in the hierarchy of organizing principles is the theory. A theory is an integrated set of principles that explains and predicts many, but not all, observed relationships within a given domain of inquiry. Because theories integrate many observations into a relatively simple whole and yet are not too general to be tested, they form the basic building blocks of science. Existing theories (or ones that you develop) may help provide you with ideas for developing your own research. The process of using a theory to generate specifi c ideas that can be tested through research is known as the deductive method. 

The Components of a Good Theory. Consider, for instance, the stage theory of cognitive development, which states that children pass through a series of cognitive stages and that children cannot perform certain activities until the appropriate cognitive stage has been reached (Piaget, 1952). This is an extremely useful theory in human development because it can be applied to many different content areas and can be tested in many different ways. 

         The utility of a theory can be judged on the basis of how well it meets some fundamental requirements. First, good theories are general, meaning that they summarize many different outcomes. Second, they are parsimonious, meaning that they provide the simplest possible account of those outcomes. The stage theory of cognitive development meets both of these requirements. It can account for developmental changes in behavior across a wide variety of domains, and yet it does so parsimoniously—by hypothesizing a simple set of cognitive stages. 

        Third, good theories provide ideas for future research. For instance, the stage theory suggested many different types of experiments in many different areas that have since been used to study cognitive development. Research has demonstrated, for instance, that children cannot conserve volume or mass until they have reached an appropriate stage of development (Piaget, 1952), that they learn about what it means to be a boy or a girl in stages (Stangor & Ruble, 1987), and that moral reasoning follows a stage sequence (Kohlberg, 1969). Taken together, these different research fi ndings, all predicted by the stage theory, provide overall support for the theory. 

           Fourth, good theories are falsifiable (Popper, 1959), which means that the variables of interest can be adequately measured and the relationships between the variables that are predicted by the theory can be shown through research to be incorrect. The stage theory of cognitive development is falsifi able because the stages of cognitive reasoning can be measured and because if research discovers that children learn new tasks gradually, rather than quickly, as they pass into a new stage, then the theory will be shown to be incorrect. In general, when a theory is falsifi ed, it will be replaced by a new, more accurate theory. 

Judgment of a Theory’s Utility. Some theories meet some of the requirements for a good theory but not others. The theory of social reinforcement, for instance, proposes that people will be more likely to subsequently perform a behavior after they have been rewarded for performing it. This is an extremely important theory because it summarizes much of everyday social behavior in a parsimonious manner and also provides ideas for testing it. For instance, the theory would predict that children would more likely share their toys if their mother praises them for doing so. 

        However, the defi nitions of “reward” in social behavior involve both external factors, such as money and praise, and internal factors, such as mood improvement and guilt reduction. Because internal factors are diffi cult to defi ne and measure, a supporter of social learning theory could easily argue that when a behavior occurs, it has been rewarded, and that when a behavior does not occur, it has not been rewarded. For instance, when a person helps a complete stranger escape from a burning building, there is obvious cost to the helper, but the potential reward is not clear. But a supporter of social reinforcement theory would say that the reward was something such as “feeling good about helping” or “avoiding guilt if one didn’t help.” In this case, the problem is that the theory is not falsifi able because the variable “reward” is defi ned as “that which increases the occurrence of behavior.” Theories in which the variables cannot be measured or in which the variables are vague enough that they cannot provide information to falsify the theory are called tautological. No single theory is able to account for all behavior in all cases. Rather, a theory is inevitably found to be limited in that it makes accurate predictions in some situations or for some people but not in other situations or for other people. As a result, there is a constant interplay between theory and data: existing theories are modifi ed on the basis of collected data, and the new modifi ed theories then make new predictions which are tested by new data, and so forth. In time a theory will either change so much that it becomes a new and different theory or be entirely replaced by another, more accurate theory. A theory survives only to the extent that it is “good enough” and no currently known alternative theory is better. When a better theory is found, it will replace the old one. This is part of the accumulation of scientific knowledge.

The Research Hypothesis

Although good theories are designed to be falsifi able, they are usually  framed too broadly to be tested in a single experiment. Therefore, scientists use a more precise statement of the presumed relationship among specifi c parts of the theory—a research hypothesis—as a basis for correlational and experimental research (remember that relationships among variables are never tested in descriptive research). Because research hypotheses are the most basic tool of the scientist, we will be spending a major part of this book discussing their development and testing. 

         A research hypothesis can be defined as a specific and falsifiable prediction regarding the relationship between or among two or more variables. The research hypothesis states the existence of a relationship between the variables of interest and the specifi c direction of that relationship. For instance: 

•  Observing violent television shows will cause increased aggressive behavior. 
•  Participating in psychotherapy will reduce anxiety. 
•  Smoking marijuana will reduce the ability to learn new information. 

         As we will discuss more fully in Chapters 10 and 11, in experimental research designs the research hypothesis involves the relationship between an independent variable (the experimental manipulation) and a dependent variable (the variable that is caused by the independent variable). The independent variable is created by the experimenter through the experimental manipulation, and the research hypothesis is that the manipulated independent variable causes changes in the measured dependent variable. Causal relationships can be depicted graphically using straight arrows that point in one direction:

In correlational research designs, both the independent variable and the dependent variable are measured. Furthermore, because it is not possible to state the causal relationships between variables in correlational designs, the terms independent variable and dependent variable are sometimes replaced with the terms predictor variable and outcome variable, respectively. The research hypothesis is that there is a correlation between the variables, and this correlation is shown using a curved line with arrows that point in both directions:

Because the research hypothesis is only a guess and is designed to be falsifiable, its validity must be tested. Moreover, there are many ways to measure the variables of interest and many ways to test the relationship between them. The major focus of this book is on how to develop research designs and test research hypotheses.