This is one of the most common and perplexing question in research. Perplexing because many don't figure out the need for a standard or the difference between a blank and a control.
Imagine you working on a plant extract that shows anticancerous property
Can you work without the 'particular' plant extract?
- That is where the test comes in!
How can you say that the plant extract contains potential substance with anticancerous property?
- That is where the control comes in!
How can you say that this substance has great anticancerous potential?
- That is where the standard comes in!
How can you be sure that this is even a plant extract?
- That is where the blank comes in!
In many of the above questions a definite answer is obtained only when we do a comparative between blank, control, standard and test. All these can be broadly classified under "samples" which are a set of factors that is required to prove the research objective.
Blank is anything without the special ingredient you want to study
Control is anything which contains a particular amount of the special ingredient you want to study
Standard is anything which contains the special ingredient in a know quantity
Test is anything that contain the special ingredient but the quantity is unknown
Comparing the result of :
Test and Standard help in calculating the quantity of special ingredient in the test
Test and Control confirms the identity of the special ingredient
Test and Control confirms the presence of the special ingredient