Reflection on Presentation 2: Sampling

On August 5, 2010, a topic on "Sampling" was presented by Normazhazlin Alzahari, Azlyn Sarafina A. Hamid and also Hanim Othman. All the three presenters have managed to present the topic clearly and answer the questions from the audience. Sampling is another branch in doing research and I believe it is important to understand and grasp the idea of sampling, population and et cetera before making the appropriate and suitable sampling methods for our research. 

I summarized whole broad idea about “Sampling” in the figure below:

 

There are two main types of sampling, which are Random Sampling and Non-Random Sampling. Let’s look at what the types of sampling are all about in the table below:

Basically, the idea of Random Sampling method is easy to catch as there are many examples that fall under this method. For instance, consider  a personnel from the Ministry’s office wishes to find out how many Secondary School Principals in Perak is keen to have Mandarin taught in as one of their subject. So, she will have to place all 100 names of secondary school, mix them thoroughly, and then draw out the names of 25 names of schools to be interviewed.

Another type of sampling is Non-Random Sampling:

Again, I would like to give the example provided by the presenters on Non-Random Sampling. Consider the Ministry wishes to send its personnel to find out how many secondary school principals in Perak is keen to have Mandarin taught in as one of their subject. There are 5 jr. Personnel in the department. They need to select only 3. Thus, 3 personnel’s were selected based on some criteria, (1) must be permanent staff and (2) at least have 5 years serving the Ministry. I thought of it as a simple and straightforward example on Non-Random Sampling  :D

 

As discussed in the class, since Purposive Sampling is largely based on the researcher’s judgement, it tends to contribute to an error of observations such as bias.

Another sub-topics discussed under “Sampling” are as below:

In doing research, it is better for us to follow the recommended sample size and we must take note that any sample that is less than 20 is too small, yet not encourage to do so. I still remember vividly Dr. Teoh said that in selecting sample size, we must ensure that we have enough energy and time to collect data. Simply say, as researchers, we should try to obtain as large as sample that we reasonably can. Pretty make sense, isn’t? 

 

Other than that, there are times when Random Sample are not been used. There are 2 reasons for this question.

First: The educational researchers are not aware of the hazards involved in generalizing where there is no random sample available.

Second: Sometimes, it is not feasible for the researcher to invest the time, money and other resources necessary to obtain a random sample. 

Till then, thank you for reading! To get the Power Point slides, click "Sampling".