Q 3. - Elementary Statistics

Question

Regarding observational studies and designed experiments: 

(a)  Describe each type of statistical study. 

(b)  With respect to possible conclusions, what important difference exists between these two types of statistical studies? 

Step-by-Step Solution

Answer

Part (a) Observational studies:  It involves the observation of what is happening or has happened in the past and then drawing conclusions for the research.

Designed experiments: 

It is a controlled experiment where the manipulation of one variable affects other variables.

Part (b) Cause and effect relationship is the main difference between the two studies.

Part (a) Step 1. Given information.

The given statement is:

Regarding observational studies and designed experiments: 

Describe each type of statistical study. 

Part (a) Step 2. Describe observational studies and designed experiments.

Observational studies:

In this type of study, the examiner simply observes what is happening or has happened in the past and draws conclusions for the research.

Designed experiments:

In this type of study, the examiner manipulates one of the variables to see how it affects the other variables. 

We can say that there is a controlled experiment going on.

Part (b) Step 1. Difference between observational studies and designed experiments.

The important difference that exists between these two types of statistical studies is their cause and effect relationship.

There is no cause-and-effect link between the variables investigated in an observational study. 

However, in a designed experimental study, the factors involved in the study have a cause-and-effect relationship.