Q.4 What Is an Experiment And How Will
Conduct Experimental Research, What Will Be The Threats To Internal And External Validity To
Minimize These Threats?
Course: : Research Methods in Education
Course Code 8604
Level: B.Ed Solved Assignment
Answer:
Non-Experimental & Experimental Research
Alright! It's time to learn something using research by … performing a non-experimental study?
Wait, wait, and wait! Is it possible to have a non-experimental study? Is that sort of like sugar-free candy? Is it something that you're supposed to have that is replaced by something that makes you scratch your head?
Before we discuss research designs, though, you need a brief walkthrough of some of the terms I am going to throw at you.
A predictor variable is the portion of the experiment that is being manipulated to see if it has an effect on the dependent variable. For example, do people eat more Gouda or cheddar cheese? The predictor variable in this is the type of cheese. Now, every time you eat cheese, you'll think about predictor variables. When I say subjects, I just mean the people in the experiment or the people being studied.
Experimental research is when a researcher can manipulate the predictor variable and subjects to identify a cause-and-effect relationship. This typically requires the research to be conducted in a lab, with one group being placed in an experimental group, or the ones being manipulated, while the other is placed in a placebo group, inert condition, or non-manipulated group. A laboratory-based experiment gives a high level of control and reliability.
Non-experimental research is the label given to a study when a researcher cannot control, manipulate or alter the predictor variable or subjects, but instead, relies on interpretation, observation, or interactions to come to a conclusion. Typically, this means the non-experimental researcher must rely on correlations, surveys, or case studies, and cannot demonstrate a true cause-and-effect relationship. Non-experimental research tends to have a high level of external validity, meaning it can be generalized to a larger population Experimental and non-experimental research design
By The U.S. Food and Drug Administration [Public domain], via Wikimedia Commons
Experimental research design
Experimental research designs are based on a clear hypothesis, the purpose of the research is to confirm or refute the validity of the hypothesis. Experimental research designs have an independent variable, a dependent variable, and a control group. Most of the experiments are conducted in a laboratory in a controlled environment. The purpose of the experiment is to find out the causation and experimental studies are causal studies. These studies answer what, why, and even how questions in the research. The experimenter can manipulate the variables and he has a control group and a placebo. The control group receives the treatment that the experimenter wants to test and the placebo group is tested without any treatment. The changes in the results of both groups are compared. The experimenter repeats the test in the same environment more than one time to get the most valid results. There are basically three different types of experiments: controlled experiments, quasi-experiments, and field experiments.
Methodology
The experimenter determines two groups to perform an experiment: one group is called the experimental group and the other group is called a placebo group. The experimental group gets the treatment and the placebo does not get any treatment. The experimental group is similar to the control group except that the control group does not get any treatment while the experimental group gets the treatment. The experimenter repeats the test twice or thrice to increase the validity of the results.
Non-experimental research design
Non-experimental research designs are carried out in natural settings, it does not involve manipulation of the situation, event, circumstances, or people. Surveys, case studies, correlation studies comparative studies, and descriptive studies are some of the examples of non-experimental research design. Longitudinal studies are also non-experimental research and the purpose of these studies is to study a situation, people, or phenomenon over some time to observe the change.
Methodology
In non-experimental research, the researcher does not manipulate the variables to be tested and therefore he cannot ascertain the effect of the independent variable on the dependent variable. A causation is established in some of the nonexperimental studies but not in all of them. The causation is established by determining that a certain variable has an impact on another variable. It can also compare the results of two or more groups or people on one or more variables
Steps in Experimental Research
The basic steps involved in conducting experimental research will be presented in this module.
Learning Objectives:
List the steps that are used in conducting experimental research.
• Describe each step involved in the process.
The following YouTube wide, Experimental Design, offers a visual representation of the process of conducting
experimental research and serves as an introduction to the steps discussed in this module.
The following list of steps explains the process of conducting experimental research in more detail. Researchers
should follow these steps to ensure the integrity of the process.
1. Select a topic. This involves simply identifying an area of interest or general subject.
2. Identify the research problem. Given the topic or subject, the researcher must now identify specific problems or questions that relate to the subject. The researcher may be familiar with the subject and may already know the problem they want to research. If the researcher is new to the topic, it may be helpful to examine literature and previous studies, as well as talk to other researchers. The problem selected should be important to the field and
be of significance to others in the discipline.
3. Conduct a literature search. Once the research problem is identified, a literature search should be conducted before proceeding to design the experiment. It is helpful to know what studies have been performed, the designs, the instruments used, the procedures, and the findings. This information will guide the researcher and help them create a project that extends or complements existing research.
4. Construct a hypothesis. In this step, the researcher states the research question as a hypothesis. This provides the basis for all other decisions in the process and therefore, it is a critical step.
5. Determine the design of the research. The researcher should review the hypothesis and verify that an experimental design is the appropriate research design needed to answer the question. Additional information regarding different types of experimental research design will be covered in the next module.
6. Determine the research methods. In this step, the researcher will identify and plan the details necessary to conduct the research. This includes identifying the test subjects, materials, data collection instruments and methods, and the procedures for conducting the experiment.
7. Conduct the research and test the hypothesis. The experimental procedures will be carried out in this phase.
8. Analyze the data. Experimental research data lends itself to a variety of potential statistical analyses. The appropriate analysis is determined by the research question and the type of data.
Surveys
The survey is the most common method by which sociologists gather their data. The Gallup poll is perhaps the most well-known example of a survey and, like all surveys, gathers its data with the help of a questionnaire that is given to a group of respondents. The Gallup poll is an example of a survey conducted by a private organization, but sociologists do their own surveys, as does the government and many organizations in addition to Gallup. Many surveys are administered to respondents who are randomly chosen and thus constitute a random sample. In a random sample, everyone in the population (whether it be the whole US population or just the population of a state or city, all the college students in a state or city or all the students at just one college, etc.) has the same chance of being included in the survey. The beauty of a random sample is that it allows us to generalize the results of the sample to the population from which the sample comes. This means that we can be fairly sure of the behavior and attitudes of the whole US population by knowing the behavior and attitudes of just four hundred people randomly chosen from that population. Some surveys are face-to-face surveys, in which interviewers meet with respondents to ask them questions. This type of survey can yield much information, because interviewers typically will spend at least an hour asking their questions, and a high response rate (the percentage of all people in the sample who agree to be
interviewed), which is important to be able to generalize the survey’s results to the entire population. On the downside, this type of survey can be very expensive and time-consuming to conduct.
Experiments
Experiments are the primary form of research in the natural and physical sciences, but in the social sciences, they are for the most part found only in psychology. Some sociologists still use experiments, however, and they remain a powerful tool of social research. The major advantage of experiments, whether they are done in the natural and physical sciences or in the social sciences, is that the researcher can be fairly sure of a cause-and-effect relationship because of the way the experiment is set up. Although many different experimental designs exist, the typical experiment consists of an experimental group and a control group, with subjects randomly assigned to either group. The researcher does something to the experimental group that is not done to the control group. If the two groups differ later in some variable, then it is safe to say that the condition to which the experimental group was subjected was responsible for the difference that resulted.
Observational Studies
Observational research, also called field research, is a staple of sociology. Sociologists have long gone into the field to observe people and social settings, and the result has been many rich descriptions and analyses of behavior in juvenile gangs, bars, urban street corners, and even whole communities.
Observational studies consist of both participant observation and nonparticipant observation. Their names describe how they differ. In participant observation, the researcher is part of the group that she or he is studying, spends time with the group, and might even live with people in the group. Several classical social problem studies of this type exist, many of them involving people in urban neighborhoods (Liebow, 1967; Liebow, 1993; Whyte, 1943). In nonparticipant observation, the researcher observes a group of people but does not otherwise interact with them. If you went to your local shopping mall to observe, say, whether people walking with children looked happier than people without children, you would be engaging in nonparticipant observation. Similar to experiments, observational studies cannot automatically be generalized to other settings or members of the population. But in many ways, they provide a richer account of people’s lives than surveys do, and they remain an important method of research on social problems.
Existing Data
Sometimes sociologists do not gather their own data but instead analyze existing data that someone else has gathered. The US Census Bureau, for example, gathers data on all kinds of areas relevant to the lives of Americans, and many sociologists analyze census data on such social problems as poverty, unemployment, and illness. Sociologists interested in crime and the criminal justice system may analyze data from court records, while medical sociologists often analyze data from patient records at hospitals. Analysis of existing data such as these is called secondary data analysis. Its advantage to sociologists is that someone else has already spent the time and money to gather the data. A disadvantage is that the data set being analyzed may not contain data on all the topics in which a sociologist may be interested or may contain data on topics that are not measured in ways the sociologist might prefer.
The Scientific Method and Objectivity
This section began by stressing the need for sound research in the study of social problems. But what are the elements of sound research? At a minimum, such research should follow the rules of the scientific method. As you probably learned in high school and/or college science classes, these rules for formulating hypotheses, gathering and testing data, drawing conclusions, and so forth help guarantee that research yields the most accurate and reliable conclusions possible. An overriding principle of the scientific method is that research should be conducted as objectively as possible. Researchers are often passionate about their work, but they must take care not to let the findings they expect and even hope to uncover affect how they do their research. This in turn means that they must not conduct their research in a manner that helps achieve the results they expect to find. Such bias can happen unconsciously, and
the scientific method helps reduce the potential for this bias as much as possible.
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