Representativeness of a sample

POST 3
In the earlier post we said that if a large population is to be considered some individuals from it should be selected that represent the population. How does one achieve that? How do we make sure that the sample we are choosing is representative of the population? This post is going to deal with exactly that – The Representativeness of a sample.

While choosing a sample, it is important that we define the characteristics of the population which should appear in the sample, i.e. we should know what it is that should be represented in the sample.

For example if a person wants to study the opinion of students on the current education system, in this the only characteristic of the population that is observed is that the population is going to be of students, but then selecting the sample becomes very difficult as there are so many students, nothing is specified with respect to their location, level etc, so technically the whole possible population of students existing comes into picture. To avoid such a situation one should try to present relevant characteristics of a population. On the other hand it should also be kept in mind that considering too many characteristics will make choosing a sample difficult as each item in the sample will need to exhibit those characteristics. In this case it could begin by stating characteristics that are going to be dealt with by the researcher, for e.g. the academic level of students, their intelligence level, their location, their gender etc.

As we go on listing the characteristics of the population we should also decide up to what extent the sample must represent the population. It means we need to decide whether all or some of the listed characteristics should appear in the sample. Ideally if all the desired characteristics appear in the sample it would render a highly representative sample. But this may not be possible sometimes due to limited costs or convenience.

Representativeness of a sample has implications on the generalisability of results, because if a sample is not representative of a population, then the results for that sample might not generalise to that population.

Or it could also be said that the results of that sample will be applicable only to that sample and other samples similar to them.

What would the researcher do?

POST 2
I know I know..you all have it figured out by now..now its my turn..

• I agree with almost all of you, according to me for a single researcher, it will be virtually impossible to achieve the objective.
• I think so because the researcher will single handedly have to interact with all the individuals in the population. Moreover a lot of time, money and energy will be required.
• In such a case what the researcher could do is, find out people who can help him/her with the study in different parts of the country. But so many people won't do work for free and may also not have the time, thus if s/he thinks of employing help then they would have to payed for it. But what if the researcher does not have the resources for it? Then what would s/he do?
• The solution of course lies, as some of you stated (you girls are good at this..), in sampling! (finally we come to it!), by sampling we mean s/he would select individuals that represents the population. This makes the population easy to handle and also saves on resources like time, money, energy.

These selected individuals constitute the so often heard sample.
The process of selecting individuals from a population is called sampling technique/ sampling strategy/ sampling design. The following illustration is a simple representation of population and sample.

But conversely it is also true that if the population under consideration is small then there is no point in sampling. So if the population itself is limited to the students of class A in schoolXYZ then there is no need to sample within this lot again.

Here is what Valerie J. Easton and John H. McColl's write about sampling and population in their Statistics Glossary.

Sampling?

POST 1
Since so many days that we have been learning about research we have heard the word “sampling”, “sample” many times. What do these words mean? Why are they so important? Why must sampling be carried out? How can it be carried out? are some of the questions that come to our mind when we hear these words. This blogging experience will help us answer them.
Before we come to how sampling is carried out we need to know what a sample is. The idea of a sample stems from the word population.

Population/Universe – all items in any field of inquiry, Kothari (2005) [see References]

Census inquiry- A complete listing of all items in the population e.g. Population census for a census inquiry it is required that when all items are considered, any possibility of chance or luck is ruled out and hence most accurate results are obtained.

One of the tasks done by the government in a population census is to count the population of India. Here the objective is to count the number of individuals in a nation. Hence listing every individual in a country is possible with the help of large number of people and government support.

• Do you think it will be possible with a single researcher who instead of listing the Indian citizens wants to find their opinion about politicians?
• If your answer is no, why do you think so?
• Could there be a solution to this problem?

While answering these questions keep in mind a person looking to buy a book of 100 stories and browsing through 4 or 5 stories and then buying it. Is there anything similar between the 2 situations? You may write about this on your own blog as a post or comment on this post itself..

Look out for the answers in the next post.

Till then happy thinking… :-)

References :
Kothari (2005) - Kothari C.R., (2005) Research Methodology: Methods and Techniques, Second edition , New Age International Publishers, 4835/24, Ansari Rd., Darya ganj, New Delhi - 110 002 (this book is available in our department library)

Lets talk....

Hello girls

This category of posts is especially with respect to the fact that some of you want to reply or comment on my blog for purposes other than doubts.

While commenting to this post,

-Just give the reference of your comment
-Copy & paste the url concerned, for e.g. if it was a question I asked you to which you are replying then copy the url of that page where that question is and paste it along with your comments

I hope this is isn't too tedious, it will help us to stay organised and give you a practice of linking ;-)

Attention attention!!

I have recently seen that some of you wanted to reply to my quesitons on your personal blogs and hence have done so in my first post.

I felt that his would deviate us from the purpose of the posts related to tasks hence,
in such situations where you all want to contact me and don't know where to categorise it, just comment in my post labled "Contact me".....but rememeber the doubts go in "Doubts"!

Redesigning your blog

Hey everyone, could not publish this post earlier due to technical problems with my PC :(
Anyway this post is with reference to some of your needs to redesign your blog or shifting the page elements of your blog..

So heres how you might go about it...

Step 1 If you are already viewing your blog, click on "Customise" on the top right hand corner of the page. If you are on your dashboard click on "Settings"

Step 2 After the above step you will be directed to the following page

You may directly be sent to the "Template" tab, if not click on "Template" then on 'page elements'. Once you go there, you can see your different page elements in form of boxes.

You can move these boxes as you wish just like we move the tool bars in 'Word', once you move your cursor on the edge of the box, a four edged arrow will appear which will allow you to move the boxes. This way you can reposition the different page elements on your blog.

Now moving on to changing colors and fonts of your blog, there is another tab in "Template" which is "Fonts and Colors", this option lets you choose colors of your choice for your blog.

If you are thinking of changing the blog template all together then there's a bit of coding that you might require to do..for this you may go to the help section of Blogger and find out what you want.

I hope any doubts with respect to moving elements on your blog or changing colors of your blog have been cleared..

Issues with uploading images and content taken from other sites

Hey girls..

I have seen that most of you are coming up with good blogs considering you all are beginners at this..

However there are certain issues we must consider while blogging. Blogs offer us a great opportunity to express ourselves, not only with words but also with images.

This is where the first issue arises, while uploading images from the web we seldom think about copyrights or related aspects.

Anything on this web is the property of someone or the other and we should keep in mind to acknowledge them while using their property.

So as long as you are writing words that are your own you don't have to worry but the moment you think of posting something that interested you on the web exactly like it is, you need to acknowledge the owner for it..same applies to images taken from the web...

So see to it that you all take care of these in future blogging!

For more information on image uploading check out:
http://help.blogger.com/bin/answer.py?answer=42492&topic=10271

See you all till then..!

Any doubts..?

Hello girls!

I thought blogs being a new tool might give rise to doubts about how to handle a blog and its different features etc. Hence..this post..

Please feel free to write about your doubts in the 'comments' section of this post labeled 'Doubts'.

You can also take help from the 'help' section of Blogger: http://help.blogger.com/ or just click on the 'Help' link given in the top right corner of the page.

Happy blogging :)

C'mon explore your blog..!

Hi there, I think after that initial bump in our blog ride all of us must have revised the process of making a blog :) !!

But seriously, now that we have made our blogs...why not explore them? I felt exploring a blog would be much better rather than teaching the features of a blog. I think writing about yourself will be a good start, just be sure to include it in "About me" where we all can read.

All you have to do is click on this icon which follows the About me title on your main blog page:

It may be any other icon signifying settings, this one's common among them. After you click on it a dialog box will open as follows:

This Dialog box contains a space for 'Description', you may enter information about yourself here in a few lines. After you enter your description don't forget to save the changes you made, or all that effort would be a waste..!

I'm waiting to get to know all of you better..!