Question

Describe the experimental method, state its advantages and disadvantages, and distinguish between independent and dependent variables.

Key Terms

experimental method

causal hypothesis

independent variable

dependent variable

experimental group

control group

random assignment

Exercises

1. What is the primary advantage of the experimental method?

2. Read the scenario and answer the questions that follow it.

In a laboratory study of sleep deprivation, researchers employed a variety of techniques to keep volunteers awake for variable amounts of time.   One group of participants was kept awake for 24 hours, and the other was kept awake for 48 hours. During periods of forced wakefulness, participants were required to engage verbal learning tasks such as memorizing the definitions of obscure English words. At the conclusion of the period of forced wakefulness, participants were allowed to sleep for as long as they wanted to. When participants awakened, researchers tested them on the learning tasks they completed during the periods of forced wakefulness. The researchers discovered that participants who were deprived of sleep for 48 hours recalled less than those who had been forced to remain awake for 24 hours.

1a. What is the independent variable?_____________________________________________

1b. What is the dependent variable?_______________________________________________

1c. What is the control group?____________________________________________________

1d. What is/are the experimental group(s)?__________________________________________

3. Why is random assignment critical to the experimental method?

Answer 1

Expirimental research

Expirimental research is mainly used in science subjects such as physics ,chemistry ,medicine ,biology and etc...Expiriment requires two variables ,one indipendant variable and the other dependant variable .It is important that in expirimental research the indipendant variable is manipulated and the effect of manipulation is observed on the dependant variable .All other extraneuos factors are completly controlled within the laboratory .It is based on research design which uses manipulation and controlled testing to understand the causal process.Expirimental methods are generally used to study the relationship between one stimulus variable and a related responsive variable while all other stimulus variables are controlled.

The variable whose effect is being subjected to study is called the indipendant variable.The response variable on which this effect is observed is called dependant variable .Thus the indipendant variable stands for the cause ,and the consequent change in the dependant variable is the effect of the cause.In performing such expiriments we try to establish certain cause -effect relationship through objective observations of the actions performed and the subsequent changes produced under controlled conditions .

Experimental group is the group of people who exposed to indipendant variable.

Control group is a seperate group from the experiment ,in which the indipendant variable being tested have no relation the outcome of the experiment .

The expirimental method is the most scientific and objective method of studying behaviour .It enriches our stock of knowledge of cause _effect relationship in the behaviour of students and provides guidelines to solve teaching -learning problems. Random assignment in expirimental method allows the researcher to place those participants into groups.

1.Advantages

• The primary advantage of the experimental method is it provides the conclusion about cause and effect relationship between variables .
• It is a systemic and scientefic approach to research in which the researcher manipulates one or more variable ,and controls and measures the other variable .

Disadvantage

• Expirimental method has limitations in its scope ,as it considers controlled and specific expirimental situations to study behaviour.As such the data donot provide insight into the total behaviour of the subject.

2.1.a sleep deprivation (forced wakefulness)

1.b .Recalled memory

1c.No control group

1.dThe group kept awake for 24 hours .The group kept awake for 48 hours.

3.Random assignment is important in expirimental method because it allows the participant to ensure that the differences between and within the groups are not systematic at the conclusion of the expiriment.