Which of the following are the techniques to control extraneous variables?
1. Elimination
2. Balancing
3. Constancy in the condition
4. Randomisation
5. Theoretical consideration
6. Counter balancing
Select the correct answer:

A research that seeks to explain a class of situations or events rather than a single one is known as

A. Basic research

B. Applied research

C. Nomothetic research

D. Idiographic research

Researchers who conduct observational studies typically use a combination of time sampling and situation sampling to achieve

A. nominal scales of measurement

B. representative samples of behaviour

C. maximum interobserver reliability

D. internally valid samples of behaviour

"Research is a systematic investigation to find answers to a problem". Who said these words?

A. Kerlinger

B. John W. Creswell

C. Burns

D. Earl Robert Bobbie

Which of the following is not a kind of independent variable?

A. Task variable

B. Environmental variable

C. Subject variable

D. Experimentel variable