The Purposes, Research Questions, and Research Hypotheses are closely related. Each Purpose should directly relate to either a Research Question or a Research Hypothesis. There is debate about whether the Research Questions and Research Hypotheses should match. Since each Research Question and Research Hypothesis has to be analyzed separately in Chapter 4, I advise that Research Questions should focus on descriptive topics only while Research Hypotheses need to be written for all comparisons. For example, if the researcher wants to determine whether males and females differ on science achievement test scores, then this should be written as a research hypothesis. A Research Question could be written as "Do males and females differ on science achievement test scores?" This would be analyzed by comparing the mean science test scores of males and females. Imagine that the average score for males is 50.6 while the average score for females is 50.2. Indeed, males scored higher, but only by 0.4 points on the test. Is this difference large enough to be significant? There will virtually always be differences between two groups, although the differences can be very small. The purpose of inferential statistics (e.g., t-tests, ANOVA, and ANCOVA) is to statistically determine whether the difference between two or more groups is significant enough to meaningfully say that there is a difference between these two groups of individuals. Therefore, analyzing this Research Question separately from the Research Hypothesis is meaningless. Do not write a Research Question that is better written as a Research Hypothesis. Instead, research questions should focus on describing a variable, such as "How often do students use a computer in the classroom?" Some research studies might not have Research Questions, which is generally ok.
Let's return to the example of the effect of telling stories on children's literacy skills. The Purposes, Research Questions, and Research Hypotheses will be described for this study.
The purposes of the study should explain the final conclusions that the research study hopes to reach. Purposes should be written as statements. Sometimes it is easier to start with the Research Questions and Hypotheses first and then write the Purposes, other times it is easier to start with the Purposes.
When writing the Purposes section, it is best to start with the general purpose of the study:
As previously stated, the Research Questions should only be written for descriptive topics only. The only research question for the purposes above is:
Typically, research hypotheses are stated as a null hypothesis. Null hypotheses are based on probability theory. In other words, there are always "chance" events that may influence scores on research instruments - perhaps one person guessed very well on an achievement test and scored higher than they should have, or another person was quite tired and misunderstood the purpose of the questionnaire. To determine whether differences in mean scores are truly different, inferential statistics (e.g., t-tests, ANOVA, ANCOVA) are used to mathematically determine the probability that the difference between two scores is due to chance. Researchers want to be quite confident that their conclusions are true, so they want a low probability that their conclusion is due to chance, typically less than 5 in 100. (This is exactly the p-value that identifies statistical significance: p<.05 means p, the probability that the result is due to chance, is less than 5 in 100.) Therefore, researchers assume the opposite of what they want to find unless they can prove with a low probability of chance that something is indeed significant. For example, the researcher hopes that computerized instruction will improve maths skills, but they have to assume that computerized instruction does not improve maths skills unless they can show their study has a low probability of chance - less than 5 in 100 (p<.05). Therefore, research hypotheses always begin with There is NO significant...
There are three basic formats for writing research hypotheses, and they each depend on the type of research design that was selected.
Causal Comparative
The key identifying factor of a causal comparative study is that it compares two or more groups on a dependent variable. Therefore, a research question for a causal comparative study will read as follows: There is no significant difference between [define the two groups] on [dependent variable]. For example, "There is no significant difference between males and females on interest in reading." If there are three or more groups, then the research hypothesis should be slightly rephrased. An example is socioeconomic status whereby children are placed into three socioeconomic status groups: high, medium, and low. Instead of defining all three groups, state that there is no significant effect of the variable: There is no significant effect of [independent variable] on [dependent variable]. For example, "There is no significant effect of socioeconomic status on children's interest in reading."
Experimental or Quasi-Experimental
They key identifying factor of experimental and quasi-experimental designs is that they examine the effect of a treatment on a dependent variable. The literacy study that examines the effect of telling stories on literacy skills should be an experimental study. Research Hypotheses for this design should read as follows: There is no significant effect of [treatment] on [dependent variable].
Correlational
Correlational designs examine the relationship between two variables within the same group of individuals. Research hypotheses for correlational designs should read as follows: There is no significant relationship between [variable 1] and [variable 2.] For example, there is no significant relationship between children's reading fluency and interest in reading.
Remember that every Purpose must have a matching Research Question or Research Hypothesis. It is best to list the Purposes in the exact order that they appear as Research Questions or Research Hypotheses. When you have finished this step, review the Purposes and identify the matching Research Question or Hypothesis, and vis versa. Once this has been completed, then it is time to start writing Chapter 3.
Below are some purposes of research studies. For each purpose, write a matching Research Question OR Research Hypothesis. (You first need to identify whether the purpose better relates to a Research Question or a Research Hypothesis. It should not be both.)
Appropriate Research Questions and Research Hypotheses are listed below.