Research Hypothesis

A research hypothesis is a specific, clear, and testable proposition or predictive statement about the possible outcome of a scientific research study based on a particular property of a population, such as presumed differences between groups on a particular variable or relationships between variables. Specifying the research hypotheses is one of the most important steps in planning a scientific quantitative research study. A quantitative researcher usually states an a priori expectation about the results of the study in one or more research hypotheses before conducting the study, because the design of the research study and the planned research design often is determined by the stated hypotheses. Thus, one of the advantages of stating a research hypothesis is that it requires the researcher to fully think through what the research question implies, what measurements and variables are involved, and what statistical methods should be used to analyze the data. In other words, every step of the research process is guided by the stated research questions and hypotheses, including the sample of participants, research design, data collection methods, measuring instruments, data analysis methods, possible results, and possible conclusions.

The research hypotheses are usually derived from the stated research questions and the problems being investigated. After the research hypotheses are stated, inferential statistical methods are used to test these hypotheses to answer the research questions and make conclusions regarding the research problems. Generally, in quantitative research designs, hypothesis testing and the use of inferential statistical methods begin with the development of specific research hypotheses that are derived from the study research questions. Research hypotheses differ from research questions in that hypotheses are specific statements in terms of the anticipated differences and relationships, which are based on theory or other logical reasoning and which can be tested using statistical tests developed for testing the specific hypotheses.

The following are two examples of research questions and possible corresponding research hypotheses. [Page 732]The first example is a nondirectional hypothesis, whereas the second is a directional hypothesis:

• Research Question 1: What differences exist in attitudes toward statistics between male and female Ph.D. candidates in the technology program?
• Research Hypothesis 1: There are statistically significant differences in attitudes toward statistics between male and female Ph.D. candidates in the technology program.
• Research Question 2: Is rapport with graduate students different for professors using a student-centered teaching method than for those using a teacher-centered teaching method?
• Research Hypothesis 2: Professors who use a student-centered teaching method will have a greater positive rapport with their graduate students than professors who use a teacher-centered teaching method.

It is important to note that in using some types of research designs, it is unnecessary and inappropriate to state research hypotheses because in these types of studies, it would be impossible to anticipate or predict the possible outcomes and findings of the study. For example, survey research that is designed to explore and describe the characteristics (e.g. attitudes, opinions) of a particular population often proceeds with no need to state research hypotheses. In addition, in qualitative research designs such as ethnographic, case studies, grounded theory, and phenomenological research, research hypotheses usually are not formulated at the beginning of the research. They are usually generated and emerged as qualitative data are collected and more understanding is gained about the phenomenon under investigation and may lead to follow-up quantitative studies to investigate the newly formed hypotheses.

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