Dr Neeta Gupta Associate Professor Department of psychology Certified Practitioner of EFT & REBT (London) & CBT (Scotland) DAV PG College Dehradun Nature of Experimental Research
It is a collection of research designs which use manipulation and controlled testing to understand causal processes. Generally, one or more variables are manipulated to determine their effect on a dependent variable.
The word experimental research has a range of definitions. In the strict sense, experimental research is what we call a true experiment . This is an experiment where the researcher manipulates one variable, and control/randomizes the rest of the variables. It has a control group , the subjects have been randomly assigned between the groups, and the researcher only tests one effect at a time. It is also important to know what variable(s) you want to test and measure.
Experimental research is commonly used in sciences such as 1.Sociology 4.Chemistry 2.Psychology 5.Biology 3.Physics 6.Medicine
Experimental Research includes few steps. Such as 1.Stating Problem 2.Formulating Hypothesis 3. Variables that are measured,calculated and compared Most importantly Experimental Research is conducted in a controlled environment . The researcher collects data and results either support or reject the hypothesis. This method of research is referred to a hypothesis testing or a deductive research method.
The deductive method is one of the methods of quantitative approach of research and is based on arriving at conclusions by narrowing down the research process at the end. In the deductive method a researcher starts with various principles and logical rules to derive a conclusion .
Deductive research aims to test an existing theory while inductive research aims to generate new theories from observed data. Deductive research works from the more general to the more specific, and inductive research works from more specific observations to more general theories.
Purpose/Goals of Experimental-Research: Demonstrate a cause and effect relationship between variables Assess the causal impact of manipulation of one or more experimental manipulations. It seek to determine the relationship between two variables i.e . IV and DV.
Experiments are conducted to be able to predict phenomenon. Typically, an experiment is constructed to be able to explain some kind of causation . Experimental research is important to society - it helps us to improve our everyday lives. /
Methods of data collection: 1.Experiment 2.Observation like experiment but no control over variables .
3.Casual interference cause and effect relationship and subjects are randomly assigned to different groups
Flow Chart of Experimental-Research Problem Hypothesis Design Sampling Tools Data-Collection Analysis Varifying Hypothesis Deriving Conclusions Experimental Research
Types of experimental research design The experimental design is defined as, “The methods used to collect data in experimental studies.” There are three primary types of experimental design: 1. Pre-experimental research design 2.True experimental research design 3. Quasi-experimental research design
1.Pre-experimental research design: In pre-experimental research, researchers follow basic experimental steps but do not use a control group. Pre-experimental research serves as the precursor, or preparation phase taking place before any true experimental research.
This research is conducted to understand whether further investigation is necessary for these particular groups or not. Pre-experimental research is further classified in three types:
1.One-shot Case Study Research Design: X O
2.One-group Pretest-posttest Research Design : O 1 X O 2 3.Static-group Comparison: X O 1 ........................... O 2
True experimental research design: True experimental research relies on statistical analysis to prove or disprove a hypothesis, making it the most accurate form of research. Of the types of experimental design, only true design can establish a cause-effect relationship within a group.
True experimental research is the actual process of experimentally researching a subject. In true experimental research, sample groups are randomly assigned, one designated control group is assigned and only one variable can be manipulated at a time. In addition, any test subjects are assigned to the control or experiment groups randomly.
. In a true experiment, three factors need to be satisfied: There is a Control Group , which won’t be subject to changes, and an Experimental Group , which will experience the changed variables. A variable which can be manipulated by the researcher. Random distribution This experimental research method commonly occurs in the physical sciences. Controlling Manipulation and randomization
Types of True Experimental Research Design: 1.Equivalent- Group Design(Posttest only) R X O 1 R O 2 2.Pretest-Posttest Control Group Design RO 1 X O 2 RO 3 O 4 3.Solomon Four-Group Design RO 1 X O 2 RO 3 O 4 R X O 5 R O 6
Quasi-experimental research design: The word “Quasi” indicates similarity. A quasi-experimental design is similar to experimental, but it is not the same. The difference between the two is the assignment of a control group. In this research, an independent variable is manipulated, but the participants of a group are not randomly assigned. Quasi-research is used in field settings where random assignment is either irrelevant or not required.
Quasi-experimental research: Used extensively in psychology and the social sciences, quasi-experimental research is similar to true experimental research but does not use a random allocation of test subjects to a control or experimental group. In fact, quasi-experimental research may lack any control group at all, making analysis of the subject more difficult.
Quasi Experimental Research Design; 1.Time Series Design O 1 O 2 O 3 O 4 X O 5 O 6 O 7 O 8 2.Equivalent Time Samaples Design X 1 O 1 X O 2 X 1 O 3 X O 4
Types of Trials in Experimental Research When conducting the randomized testing in experimental research, researchers can use either single- or double-blind trials to further help eliminate bias. Single-blind trials: In a single-blind trial, test subjects do not know in which test group they are in or what they are having done to them as part of the experiment. In fact, test subjects only find out what group they tested in upon completion of the study. .
Double-blind trials: In a double-blind trial, neither participants or researchers know which test subjects are in an experimental or control group. This type of study helps reduce bias on the part of the researchers
Experimental research is most useful for 1.Drawing conclusions 2.Regarding interventions and treatments 3.Establishing whether or not one or more factors cause a change in an outcome. Advantages of Experimental-Research