Week 4
This module will introduce the basics of choosing an appropriate research design and the key factors that must be considered. You will consider your project and submit an outline of your research design for feedback.
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Objectives:After successful completion of this module, faculty will be able to:
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Basic Research Design
Once the research question has been formulated, it is critical that you select the appropriate research methodology to answer the question. The type of research question will typically dictate the methodology that will be employed. The reliability and validity of the results depends on upon proper selection of the research approach and design. Before deciding on a particular research design, it is important that you are familiar with research terminology that you will need to consider when choosing your methodology. Two of the most important concepts are variables and sampling. The following discussion of these topics will help you consider variables and sampling in relation to your research project and will ultimately assist you in choosing a research design.
Types of Variables
It is very important when designing a research study that you fully understand the variables in the study in order for the results to be valid and have meaning. A variable is something in the study that can be changed such as a characteristic or a value. The most common types of variables, especially when study cause and effect relationships, are the independent and dependent variables. The independent variable is the one that can be controlled or manipulated. The dependent variable is the one that is measured by the experimenter. For example, if a researcher wanted to study the effects of fertilizer on plant growth, the independent variable would be the amount of fertilizer and the dependent variable would be the height of the plant. It is very important that the research can identify these variables in a study and describe how these variables are measured and defined. For practice in identifying these variables, this YouTube video below defines dependent and independent variables and provides numerous examples and opportunities to practice identifying each variable in sample research problems: Variables
The following YouTube video provides additional and more detailed information regarding other types of variables used in research studies. This 20 minute video contains a Research Methods lecture that uses examples in psychology to discuss types of variables.
Sampling
Researchers often cannot study every member of a population or group. Rather, they collect data from a subset of that population or group which is called a sample. The data collected and observations made are used to make inferences about the entire population or group with the idea that the sample will be representative of the larger population. There are two main approaches to sampling – probability sampling and nonprobability sampling. Probability sampling is when all members of a population or elements of a group have the same opportunity and chance of being included in the study. Following are the three most common types of probability sampling:
- Simple random sample – all members of a population or elements have an equal chance of being selected and sampling is done is a single staged time frame where each member is selected individually.
- Systematic samples – taken by starting with a randomly selected member of population or element and then selecting every nth member of the population. For example – selecting ever 50th name on a list of community members.
- Cluster samples – Starts with first selecting groups of elements or members of populations in clusters (schools, people living on particular block, etc..) and then selecting individuals from each cluster.
Nonprobability sampling occurs when members of the study or elements of a group are selected based on availability (perhaps they volunteered) or on the researcher’s judgment that they will be representative. This is often called convenience sampling because researchers use whatever individuals are available.
In order for the results to be valid, other factors that must be considered in sampling are the response rate, sampling size and sampling error. For more information about variables and sampling, see the resources available on GCU Research Tutorial - Sampling & Variables.
If you need assistance in determining your needed sample size, see Research in the Real World: Sample Size.
Quantitative and Qualitative Designs
There are two main approaches to a research problem - quantitative and qualitative methods. Quantitative methods are used to examine the relationship between variables with the primary goal being to analyze and represent that relationship mathematically through statistical analysis. This is the type of research approach most commonly used in scientific research problems. Qualitative methods are chosen when the goal of the research problem is to examine, understand and describe a phenomenon. These methods are a common choice in social science research problems and are often used to study ideas, beliefs, human behaviors and other research questions that do not involve studying the relationship between variables. Once the main approach to the research problem has been determined, there are several research designs for each type of approach that may be considered.
Choosing a Design
The following table lists and describes the most common research designs used at Grand Canyon University. Different research books will use different terms for similar types of research. However, the research designs identified in this document are fairly common in terms of their use and their terminology.
Types of Research Designs
Quantitative Designs | Qualitative Designs | ||
Design | Focus | Design | Focus |
Correlational | Explore the relationship between two or more variables through a correlational analysis. The intent is to determine if and to what degree the variables are related. It does not imply one causes the other. | Case Study And Historical | Intent is to study and understand a single situation, which could be a leader, a classroom, a process, program, activity. Collect a variety of material in a specific and bounded time period. This is also used for historical studies, when collecting historical data to understand and learn from the past. |
Causal Comparative | Compare two groups with the intent of understanding the reasons or causes for the two groups being different. | Narrative | Describe the lives of individual(s) to get meaning from them. |
Experimental | Test an idea, treatment, program to see if it makes a difference. There is a control group and a test group. Individuals are randomly assigned to the two groups. One group gets the treatment (test group) and the other group (control group) does not get the treatment. There is a pre and post-test for both groups in a traditional experimental design. | Grounded Theory | The focus is to develop an understanding of a phenomenon or situation in order to be able to develop a theory/model for items such as factors, a form of interaction, or a process. |
Quasi-experimental | It is the same as experiment in that there is a control and test group. However, current groups are used as is rather than randomly assigning people to the two groups. Both groups receive the pre and post- test in a traditional design. | Phenomenology | Studies a human experience at an experiential level such as understanding what it means for a woman to lose a child. It is about understanding the essence or meaning of the experience. |
Mixed Research Designs A mixed research design involves having both a quantitative design and qualitative design. Mixed designs is the best approach if the study requires both quantitative and qualitative designs to address the problem statement. Mixed design studies take significantly more time, more resources, and require the researcher to develop expertise in qualitative analysis techniques and quantitative analysis techniques. Qualitative studies can use numbers, counts and even descriptive statistics. Using numbers does not mean the study has to be quantitative or mixed methods. | |||
Your assignment for Week 4 is to consider your research design. Create an outline of your plan for your design and submit it here. |
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