Question

Discuss the strengths and weaknesses of correlational and regression studies; discuss concepts such as positive and negative correlations, correlation coefficients, confounding, and causality.

Answer 1

Correlational studies:
Strengths -
(1)Helpful in calculating the strength of a relationship between variables.
(2) It is useful as a pointer for more detailed research.
Weaknesses -
(1)Cannot assume cause and effect, a strong correlation between variables may be misleading.
(2) Lack of correlation may not mean there is no relationship at all, it could be non-linear.

Regressional studies:strengths -
(1) It provides a functional relationship between two or more related variables with which one can easily estimate the unknown values of one variable from the known values of another variable.
(2) It provides a measure of errors of estimates made through the regression line.
weaknesses-
(1) The cause and effect relationship between the variables remains unchanged.
(2) It cannot be used in case of qualitative phenomenon i.e. honesty, crime etc.

Positive and Negative correlation

A correlation is said to be positive correlation if one variable increases then the other also increases and when one variable decreases, the other also decreases. For example, the length of an iron bar is dependent on temperature and shows positive relation as with an increase in temperature, length also increases.

Correlation is said to be negative correlation if one variable increases the other decreases and vice versa. For example, with the increase in pressure, the volume of gas will decrease.

Correlation Coefficients:

A correlation coefficient is used to find how strong a relationship is between the data.

Cofounding :
Cofounding is that extra variable in an experimental design that correlates with both the dependent and independent variables.

Causality :
It is a genetic connection to the phenomena through which one thing (the cause) under certain conditions gives rise to something else (the effect).