Experimental MethodExperimental Method

METHODS IN PSYCHOLOGYMETHODS IN PSYCHOLOGY

1.Experimental Method1.Experimental Method

2.Observation Method2.Observation Method

3.Clinical Method3.Clinical Method

EXPERIMENTAL RESERACHEXPERIMENTAL RESERACH

Experimental research is one where the Experimental research is one where the variables can be directly manipulated by the variables can be directly manipulated by the experimenter.experimenter.

Experimental ResearchExperimental Research

Laboratory ExperimentsLaboratory Experiments Field ExperimentsField Experiments

EXPERIMENTAL METHODEXPERIMENTAL METHOD

DefinitionDefinition

Cattell (1965) defined experimental method as a serial Cattell (1965) defined experimental method as a serial process in which experimenter sets the condition of process in which experimenter sets the condition of observation isolates the facts to be observed, observation isolates the facts to be observed, manipulates and control the relevant variables in set manipulates and control the relevant variables in set and controlled conditions.and controlled conditions.

EXPLAINING DEFINITIONEXPLAINING DEFINITION

Serial processSerial process Sets the condition of observationSets the condition of observation Isolates the facts to be observedIsolates the facts to be observed Manipulates the relevant variablesManipulates the relevant variables In set and controlled conditionsIn set and controlled conditions

STEPS OF EXPERIMENTATIONSTEPS OF EXPERIMENTATION

STATING THE PROBLEMSTATING THE PROBLEM• Qualities of a problemQualities of a problem1.1. It must be solvable.It must be solvable.

2.2. Answerable with the tools present.Answerable with the tools present.

3.3. The problem may be concerned with any aspect of The problem may be concerned with any aspect of behaviour whether it is judged to be important or behaviour whether it is judged to be important or

trivial.trivial.

•Sources of a ProblemSources of a Problem

1.1. Studying past researchStudying past research

2.2. JournalsJournals

3.3. An experimenter may select problem of his own An experimenter may select problem of his own

interestinterest..

Formulating the HypothesisFormulating the HypothesisHypothesis is a tentative solution to the ProblemHypothesis is a tentative solution to the Problem

Types of HypothesisTypes of Hypothesis

UniversalUniversal ExistentialExistential PositivePositive NegativeNegative NullNull

• Sources for Formulation of HypothesisSources for Formulation of Hypothesis1.1. Abstract SimilaritiesAbstract Similarities

2.2. Forming AnalogiesForming Analogies

3.3. Extrapolating from previous research Extrapolating from previous research

Characteristics of a Good HypothesisCharacteristics of a Good Hypothesis

1.1. TestableTestable

2.2. General harmony with other hypothesis in the field General harmony with other hypothesis in the field of investigationof investigation

3.3. ParsimoniousParsimonious

4.4. Answer particular problem addressed and not some Answer particular problem addressed and not some other oneother one

5.5. Logical simplicityLogical simplicity

6.6. Expressed in quantified formExpressed in quantified form

7.7. Large number of consequencesLarge number of consequences

8.8. General in scopeGeneral in scope

Selecting ParticipantsSelecting ParticipantsThe type of participant studied will be The type of participant studied will be

determined by the nature of the problem.determined by the nature of the problem.

Assigning Participants to GroupsAssigning Participants to GroupsParticipants should be assigned to groups in Participants should be assigned to groups in

such a way that the groups will be such a way that the groups will be approximately equivalent at the start of the approximately equivalent at the start of the experiment. It is done by randomization. The experiment. It is done by randomization. The group receiving experimental treatment is group receiving experimental treatment is called experimental group and the other group called experimental group and the other group is called control group.is called control group.

Defining the VariablesDefining the VariablesVariable is anything that can change its value.Variable is anything that can change its value.

Types of VariablesTypes of Variables

Independent DependentIndependent Dependent OrganismicOrganismic ContinuousContinuousDiscreteDiscrete

Determining Influence of Independent Determining Influence of Independent VariableVariable

To determine the influence of Independent To determine the influence of Independent variable the experimenter administers one variable the experimenter administers one value of it to experimental group and the value of it to experimental group and the other to control group. For this purpose there other to control group. For this purpose there are several approaches-:are several approaches-:

1.1. Between group designBetween group design2.2. Within group designWithin group design3.3. Direct manipulationDirect manipulation4.4. Manipulation by selectionManipulation by selection5.5. Single Vs Factorial designSingle Vs Factorial design

Controlling extraneous variablesControlling extraneous variablesThe experimenter must hold constant all the The experimenter must hold constant all the

variables that may affect dependent variable variables that may affect dependent variable except independent variable.except independent variable.

• TECHNIQUES OF CONTROLTECHNIQUES OF CONTROL

1.1. MatchingMatching

2.2. RandomizationRandomization

3.3. CounterbalancingCounterbalancing

4.4. Randomized blockRandomized block

5.5. Single and Double blind controlSingle and Double blind control

Data CollectionData Collection

Types of ExperimentTypes of Experiment

UnivariateUnivariate BivariateBivariate MultivariateMultivariate

Conducting Statistical TestsConducting Statistical TestsBy confronting the hypothesis with the dependent By confronting the hypothesis with the dependent

variable values of two groups the experimenter can variable values of two groups the experimenter can determine if the hypothesis accurately predicted the determine if the hypothesis accurately predicted the results.For this we must resort to statistics like results.For this we must resort to statistics like computing mean, median, chi-square etc.computing mean, median, chi-square etc.

Generalizing the HypothesisGeneralizing the Hypothesis

The experimenter may believe that the hypothesis The experimenter may believe that the hypothesis is true for specific condition under which it was is true for specific condition under which it was tested. He further generalize the result on tested. He further generalize the result on population concerned.population concerned.

Making PredictionMaking PredictionA hypothesis may be used to predict certain events A hypothesis may be used to predict certain events

in new situations .in new situations .

ReplicationReplication

Additional experiment is conducted in which the Additional experiment is conducted in which the method of the first experiment is repeated.method of the first experiment is repeated.

ExplanationExplanationThe relationship between the Independent and The relationship between the Independent and

Dependent variable may be formulated as an Dependent variable may be formulated as an empirical law, particularly if its relationship has been empirical law, particularly if its relationship has been confirmed in replication of experiment and finally we confirmed in replication of experiment and finally we explain an empirical law by means of some explain an empirical law by means of some appropriate theory. appropriate theory.

Merits of Experimental methodMerits of Experimental method1.1. Artificial situations almost similar to natural Artificial situations almost similar to natural

conditions can be created in the lab. Hence it saves conditions can be created in the lab. Hence it saves time.time.

2.2. It is a scientific method.It is a scientific method.3.3. Problems are objectively studied.Problems are objectively studied.4.4. Problem can be replicated thus the results can be Problem can be replicated thus the results can be

verified.verified.5.5. Results are objective hence free from personal Results are objective hence free from personal

feelings, biases, prejudices of the experimenter as feelings, biases, prejudices of the experimenter as well as the subject.well as the subject.

6.6. Results are pure and dependable therefore the Results are pure and dependable therefore the predictions can be made.predictions can be made.

Demerits of Experimental MethodDemerits of Experimental Method1.1. In artificial environment subjects may not In artificial environment subjects may not

behave naturally.behave naturally.

2.2. It is very difficult to all the control It is very difficult to all the control extraneous variables properly.extraneous variables properly.

3.3. Limited scope on several problems e.g. Limited scope on several problems e.g. social problems.social problems.

Thank YouThank You