Day 6- Is randomness only of ONE type?

Hello Hemangi,
Good to see you after a long time. Im sure malaysia in all its splendour is keeping you busy not to mention the amazing work that you are doing there. Trust you and chitra are doing great. Do send pictures if you can...Well back to sampling...

Eg 1
A researcher wants to find out the opinion of primary school teachers on the increasing amounts of size and weight of children’s’ schoolbags. She decides to carry out a survey for this purpose. Out of the 1000 primary school teachers in Mumbai, she decides to select 300 teachers randomly for her study.
-- Points of Difference
1. The researcher is conducting a survey
2. The sample is chosen by the simple random method. As she simply selected 300 teachers randomly out of a list of 1000.

Eg 2
A teacher at a university wants to find out whether there is any difference caused in the academic achievements of students after using 2 different kinds of CAI packages - one with linear interactivity and the other with non-linear interactivity. She decides to carry out the study on her own batch of 50 students. Since there are 2 kinds of CAI packages to be implemented, she makes 2 groups in the following way:She lists everyone’s names on chits, and draws one chit out of the lot and writes that name under a column named linear CAI and puts that chit aside. Then she picks another one, this time writing the name under a column named non-linear CAI. She proceeds in this way until all chits have been randomly distributed under the 2 columns and she is ready with 2 groups of students for her study.
-- Points of Difference
1. The research is conducting an experiment where by 2 independent variables have been selected.
2. The sample chosen here is also randomly selected but not by the simple random selection. This looks like a systematic sampling method as she is randomly selecting the names from the lot but systematically alotting those name individually to one group and then to the other.

Ref: http://metca6research.blogspot.com/ Is randomness only of ONE type?