Research Design: Experimental and Correlational Methods PDF

RESEARCH DESIGN EXPERIMENTAL AND CORRELATIONAL  When scientists passively observe and measure phenomena it is called correlational research. Here, researchers do not intervene and change behavior, as they do in experiments. In correlational research, the goal is to iden...

RESEARCH DESIGN EXPERIMENTAL AND CORRELATIONAL  When scientists passively observe and measure phenomena it is called correlational research. Here, researchers do not intervene and change behavior, as they do in experiments. In correlational research, the goal is to identify patterns of relationships, but not cause and effect. Importantly, with correlational research, you can examine only two variables at a time, no more and no less.  In a correlational study, the researcher would ask children (or their parents) to document the amount of violent television the child watches in a set time period (perhaps one week) and then the researcher would observe the children's behavior, recording instances of aggression. The researcher does no intervention. Suppose the researcher gets the following results, where each row in the table below corresponds to the scores of one child. Do you notice any pattern between the two columns of numbers? If you knew how much violent television a child watched, would you be able to predict the child's aggression score? EXAMPLE OF DATA-CORRELATIONAL STUDY Hours per Week Spent Watching Aggression Score (least aggressive=1, Violent TV most aggressive=10) 0 1 3 2 8 5 9 4 11 7 18 9 41 10  The table shows a strong positive correlation because an increase in the amount of violent television is usually associated with an increase in aggression score. We would predict that children who watch more violent television are likely to score higher on the aggression scale. But can we conclude that watching violent television causes the children to be more aggressive? Although this conclusion is certainly consistent with the results, it cannot be adopted because it is not the only plausible interpretation. It could be that children who are more aggressive choose to watch more violent television (aggression causes the television viewing habits rather than the other way around) or that television habits and aggression are not causally related, but appear to go together because both are associated with a third factor, such as amount of parent supervision. Perhaps children who are not supervised are more likely to watch more violent television, as well as score higher on an aggression scale. Correlational studies do not allow us to determine which of these interpretations is the correct one. To do that, we would have to do an experiment. EXEPRIMENTAL RESEARCH Experiments are designed to test hypotheses (or specific statements about the relationship between variables) in a controlled setting in efforts to explain how certain factors or events produce outcomes. A variable is anything that changes in value. Concepts are operationalized or transformed into variables in research which means that the researcher must specify exactly what is going to be measured in the study. EXAMPLE In an experiment the researcher exposes the children to various types of television and then monitors their behavior for aggression. In a simple experiment, a researcher would create two groups of children (an experimental and a control group) through randomization (each participant has an equal chance of getting in either group). Randomization is used as a control so that the two groups are roughly equivalent at the start of the experiment. (see the section on Identifying variables and confounds for more information) The experimental group is shown violent television, and under identical conditions, the control group is shown nonviolent television.  Afterwards the researcher sees whether children in the experimental group score higher on the aggression scale than children in the control group. If they do, the experimenter can conclude that watching violent television makes children aggressive (provided the researcher has controlled for confounds and extraneous variables.  Survey research design is a fundamental method in the field of research where the primary method of data collection is through surveys. This type of research design allows researchers to collect structured data from individuals or groups to gain deeper insights into their thoughts, behaviors, or experiences related to a specific topic. Online surveys or forms typically consist of structured questions, each tailored to gather specific information, making them a versatile tool in both quantitative and qualitative research.  Survey design is highly valued in research because it is an accessible and efficient way for respondents to share their perspectives. By leveraging survey research, organizations can quickly gauge public opinions, understand trends within a population, and identify issues or areas for improvement. This method is widely used in academic, business, and government research to uncover data that can lead to actionable solutions or further study.  One of the key strengths of survey research is its ability to provide a snapshot of trends or opinions within a population, allowing researchers to generalize findings and make informed decisions. Additionally, surveys can be used to test hypotheses, track changes over time, or serve as the foundation for more in-depth studies. As a result, survey research design remains a cornerstone of modern research methods.  Field research is defined as a qualitative method of data collection that aims to observe, interact and understand people while they are in a natural environment. For example, nature conservationists observe behavior of animals in their natural surroundings and the way they react to certain scenarios. In the same way, social scientists conducting field research may conduct interviews or observe people from a distance to understand how they behave in a social environment and how they react to situations around them.  Field research encompasses a diverse range of social research methods including direct observation, limited participation, analysis of documents and other information, informal interviews, surveys etc. Although field research is generally characterized as qualitative research, it often involves multiple aspects of quantitative research in it. HYPOTHESIS AND TYPES OF HYPOTHESES What is hypothesis? A hypothesis states your predictions about what your research will find. It is a tentative answer to your research question that has not yet been tested. For some research projects, you might have to write several hypotheses that address different aspects of your research question.  A hypothesis is not just a guess – it should be based on existing theories and knowledge. It also has to be testable, which means you can support it through scientific research methods (such as experiments, observ ations and statistical analysis of data). Variables in hypotheses Hypotheses propose a relationship between two or more types of variables. An independent variable is something the researcher changes or controls. A dependent variable is something the researcher observes and measures.  If there are any control variables, extraneous variables, or confounding variables, be sure to jot those down as you go to minimize the chances that research bias will affect your results. A control variable is any variable that's held constant in a research study. An extraneous variable is any factor that is not the independent variable that can affect an experiment's dependent variables , which are the controlled conditions Example: Daily exposure to the sun leads to increased levels of happiness. In this example, the independent variable is exposure to the sun – the assumed cause. The dependent variable is the level of happiness – the assumed effect. Types of Hypothesis Hypothesis can be classified as follows: Null Hypothesis Simple hypothesis Directional hypothesis Complex hypothesis Non-directional hypothesis Causal and associative hypothesis Null Hypothesis It states that one variable doesn't affect the other variables being studied. A null hypothesis asserts that two factors or groups are independent of each other and that some traits of a population or process are identical. To contradict or invalidate the null hypothesis, we must assess the likelihood of the alternative hypothesis in addition to the null hypothesis. Simple Hypothesis There are two types of variables i.e, dependent and independent variables. A simple hypothesis shows the relationship between the dependent and independent variables. For example, if you pump petrol into your bike, you can go for long rides. Here bike is the dependent variable and petrol is the independent one. Directional Hypothesis A directional hypothesis is a researcher's prediction of a positive or negative change, relationship, or difference between two variables in a population. This statement is often supported by prior research, a widely established theory, considerable experience, or relevant literature. For example, students who do proper revision and assignments could score more marks than the students who skipped. Here, we already know the process and its impact on the outcome. This is what we call a directional hypothesis. Complex Hypothesis The complex hypothesis shows the relationship that comes between two or more dependent and independent variables. For example, if you pump petrol in your bike, you can go for long rides, also you become an expert in riding a bike, you explore more places and come across new things. Non-directional Hypothesis There is no theory for this kind. Unlike the directional hypothesis, there are no predictions. We can say there is a relation between the variables but prediction and nature are unknown. Causal and Associative Hypothesis If there is a change in one variable and as a result, it affects the other variable, then we say it is associative. Meanwhile, the causal hypothesis comes into play when the cause and effect interaction occurs between two or more variables. QUANTITATIVE AND QUALITATIVE RESEARCH  QUALITATIVE RESEARCH Qualitative research is expressed in words. It is used to understand concepts, thoughts or experiences. This type of research enables you to gather in-depth insights on topics that are not well understood. Common qualitative methods include interviews with open-ended questions, observations described in words, and literature reviews that explore concepts and theories. Qualitative research is also at risk for certain research biases including the Hawthorne effect, observer bias, recall bias, and social desirability bias. What Is the Hawthorne Effect? The Hawthorne Effect is the supposed inclination of people who are the subjects of an experiment or study to change or improve the behavior being evaluated only because it is being studied and not because of changes in the experiment parameters or stimulus.  QUANTITATIVE RESEARCH Quantitative research is expressed in numbers and graphs. It is used to test or confirm theories and assumptions. This type of research can be used to establish generalizable facts about a topic. Common quantitative methods include experiments, observations recorded as numbers, and surveys with closed-ended questions. Quantitative research is at risk for research biases including information bias, omitted variable bias, sampling bias, or selection bias. RESEARCH DESIGN MIXED METHOD +Mixed methods research combines elements of quantitative research and qualitative research in order to answer your research question. Mixed methods can help you gain a more complete picture than a standalone quantitative or qualitative study, as it integrates benefits of both methods. +Mixed methods research is often used in the behavioral, health, and social sciences, especially in multidisciplinary settings and complex situational or societal research. EXAMPLE +How do interviews about job satisfaction at Company X (qualitative) help explain year-over-year sales performance and other KPIs (quantitative)? +How do average hospital salary measurements over time (quantitative) help to explain nurse testimonials about job satisfaction (qualitative)?  ACTION RESEARCH +Action research is a research method that aims to simultaneously investigate and solve an issue. In other words, as its name suggests, action research conducts research and takes action at the same time. It was first coined as a term in 1944 by MIT professor Kurt Lewin. A highly interactive method, action research is often used in the social sciences, particularly in educational settings. +Particularly popular with educators as a form of systematic inquiry, it prioritizes reflection and bridges the gap between theory and practice. Due to the nature of the research, it is also sometimes called a cycle of action or a cycle of inquiry. +Types of action research +There are 2 common types of action research: participatory action research and practical action research. +Participatory action research emphasizes that participants should be members of the community being studied, empowering those directly affected by outcomes of said research. In this method, participants are effectively co- researchers, with their lived experiences considered formative to the research process. +Practical action research focuses more on how research is conducted and is designed to address and solve specific issues. +Both types of action research are more focused on increasing the capacity and ability of future practitioners than contributing to a theoretical body of knowledge.  RESEARCH METHODOLOGY CONTENTS... Definition of research and its importance Steps in the process of research Identifying a research problem Reviewing related literature Understanding Hypothesis ACKNOWLEDGE MENT Presentation taken from the teaching material by Prof. Rahul Kundu Department of Bioscience, Saurashtra University