Experimental Method

Experimental Method

This is the most scientific and objective method of studying behavior. Actually it is this method which is responsible for assigning the status of science to psychology.

          Here, the emphasis is on experimentation. Experimentation consists of objective observation of actions performed under pre-arranged or rigidly controlled conditions are drawn and theories or principles are formed the following are the essential features of the experimental method:-

1.     Psychological experiments are always conducted on living organism in contrast to experiments in physical sciences which are generally conducted on inorganic or dead subjects.

2.     Psychological experiments performed in this method essentially require two persons, the experimenter and the subject or the person whose behavior is observed.

3.     The key factor in this method is the controlling of the conditions or variables. By this control we can eliminate irrelevant conditions or variable and isolate relevant ones. In this way we become able to observe the causal relation between two phenomena keeping all other conditions almost constant. For example, if we try to study the effect of intelligence on academic achievement by experimental method, we will need to discover the causative relation between the two phenomena – intelligence and academic achievement by experimental one of these variables, the effect of which we want to study, will be called independent variable and the other as dependent variable. Thus independent variable stands for the cause and dependent variable is characterized as the as the effect of that cause. The other conditions like study hobbit sex,   socio-economic conditions, parental education home environmental, health. Past, learning memory etc. which exercise desirable impact upon one’s achievement besides his intelligence are termed as intervening variables. In experimentation all such in tervening variables are two be controlled i.e made constant or equalized and the effect of only the one independent variable like intelligence in the present case, is studied on one or more dependent variables. For this we try to change and very the independent variables. For this it brings concomitant changes in the dependent variable or variables. These changes are objectively observed and measured and on their basis conclusion are drawn.

In an experimental method there are various experimental designs which are followed by the investigator to control the variable and measure their effect. Some of the main techniques are:-

a)     The control – Test method (method of difference)- in this method we try to differentiate by observing the performance under different conditions. First we observed under normal conditions and then again with one condition changed. In this experimental design, there is no need of having two different groups of subjects for the experiment. Only the measures can be taken several times under different conditions.

Examples: - suppose we want to know whether students can do better on an intelligence text under the in influence of a specific drug.

          For its finding we will take only one group of some students preferably of the same age, sex, health conditions etc. the process of experimentation, then will run in the following steps:-

1.     These students can be given sugar capsules. After giving the capsules they can be tested on some intelligence test. This will make the initial testing under normal conditions.

2.     Sometimes later they can be given drug capsules and tested on the same intelligence test. This will make a test under changed conditions.

3.     The I.Q scores under these two situations are noted down and the difference is calculated. If any significant differences are found, it is attributed to the influence of the drug.

b)    Control – Group method: - control test method possesses a serious draw back known as positive practice effect in control – group method we can minimize the practice effect. Here, two separate groups, known as experimental groups- are taken. They are equated or matched on various traits like age, sex, intelligence and other personalities characteristic. There is one to one correspondence in the two equated groups. Now, the one group – control-group – is given drug capsules and tested on the same intelligence test. Then the differences in the intelligence scores of the groups are calculated. In case we find some significant differences, they are attributed to the effect of drug.

c)     Rotation method :- This method consist in presenting two or more stimulating situations to the experimental subjects in as many sequences as necessary to control the serial effect or fatigue or practice.

Two alternatives can be adopted.

1.     We may obtained half the measures for condition A, all the measures for conditions B, and then other half of the measure for condition A. this technique is sometimes called the ABBA order.

2.     Another alternative is to separate the subject in two. A and B where as the other group receives treatment B and then A. both sets of A result us and both set of B results may then be combined send the difference between then calculated.

Limitations of experimental method.

1.     Behavior under laboratory controlled conditions may be or is different from spontaneous or natural behavior, so it becomes artificial when producted in laboratory.

2.     It is also debatable whether experimental results obtained from studies on animals are applicable to human beings or not.

3.     It is a costly and time – consuming method.

4.     We cannot perform experiments for the all the problem that are raised in heterogeneous subject- matter at psychology.

Aswathy. A

Social Science