✰ Experimental research is designed for establishing causal relationships. Experimental research can also be explained as a “cause and effect” model.
✰ Experimental research is systematic and a scientific method of conducting research using two variables: independent and dependent. Independent variables can be manipulated to apply to dependent variables and the effect is measured.
✰ An experiment research is a procedure carried out to accept or reject a Hypothesis.
✰ Experimental research is a quantitative research.
✰ Characteristics of Experimental research: 1) Manipulation 2) Control 3) Observation
Steps of work conducted in experimental research:
✰ Make randomly assigned two groups. The group which is exposed to usual conditions, it is termed a ‘control group’ and but the group which is exposed to some special condition, it is termed an ‘experimental group’ or ‘Treatment group’.
✰ Now experiment is going to done on Experimental or Treatment group.
✰ An independent variable is manipulated or changed.
✰ Extraneous variable are controlled.
✰ Observe the effect of independent variable on the dependent variable.
✰ And at the end, compare two groups
There are following variables in experimental research:
✰ The variable upon which the effects of changes are observed is called the dependent variable, which is observed but not manipulated by the researcher.
✰ Dependent variables are also called the response or outcome variables.
✰ Independent variables are the cause of Dependent variable.
✰ It is the variable manipulated or changed by the researcher in an experiment and then observe the effect of independent variable on dependent variable.
✰ Independent variables are also known as the experimental, manipulated, or treatment variables.
✰ Independent variables that are not related to the purpose of the study, but may affect the dependent variable are termed as extraneous variables.
✰ Extraneous variable must be controlled so that the researcher can be sure that the cause of dependent variable is only because of independent variable.
✰ One important characteristic of a good research design is to minimise the influence or effect of extraneous variables on dependent variable.
✰ When the dependent variable is not free from the influence of Extraneous variable(s), the relationship between the dependent and independent variables is said to be confounded by an extraneous variable(s).
✰ The extraneous variable that researcher forget to considered. But this variable affects the dependent variable.
Experimental and control groups:
✰ In an experimental research when a group is exposed to usual conditions, it is termed a ‘control group’, but when the group is exposed to some novel or special condition, it is termed an ‘experimental group’ or ‘Treatment group’.
✰ Example: suppose a researcher wants to study whether intelligence affects reading ability for a group of students our researcher randomly selects 50 students from a group of students who are to take a course in statistics and then divides them into two groups by randomly assigning 25 to Group A, the usual studies programmer, and 25 to Group B, the special studies programmer. At the end of the course, he administers a test to each group in order to judge the effectiveness of the training programmer on the student’s performance-level. This is an example of experimental hypothesis-testing research.
✰ The Group A can be called a control group and the Group B an experimental group.
Types of experimental research design
There are three primary types of experimental design:
1) Pre-experimental research design. 2) True experimental research design. 3) Quasi-experimental research design
Pre-experimental research design:
✰ It is the simplest form of experimental research design.
✰ It is treated with no control group.
✰ In pre-experimental research design, effect of an independent variable are observed on dependent groups.
✰ It follows experimental research design step but the main difference is that it doesn’t include a control group.
✰ There is no comparison between control group and experimental group as it does not include control group.
✰ Example: An example of a pre-experimental design would be a gym trainer implementing a new training schedule for a trainee.
True experimental research design:
✰ Experimental research design depends on statistical analysis to approve or disprove a hypothesis.
✰ It is the most accurate form of research.
✰ True experimental research can produce a cause-effect relationship between an independent and dependent variable.
✰ Effect of an independent variable are observed on dependent groups.
✰ There is comparison done between control group and experimental group as it must include control group.
This experiment requires the fulfillment of 3 components:
≫ A control group (unchanged) and an experimental group (to undergo changes in variables) ≫ Random assignment ≫ Variables can be manipulated
3) Quasi experimental research design:
✰ The word “quasi” means near, partial or half.
✰ Like a true experimental, a quasi-experimental design aims to establish a cause-and-effect relationship between an independent and dependent variable but quasi-experiment does not rely on random assignment.
✰ It is conducted in real world, in a natural setting i.e. in non-controlled way.