 My friends, my name is Arpata Karwa and welcome to another important video in the UGC-NET Paper 1 series. In this particular series, we are covering all the units of UGC-NET Paper 1 in detail and currently we are on our unit 2 that is research aptitude. So far in this unit, I have covered so many topics in two videos. So in the first video, I discussed what is research, types of research and characteristics of good research. In the second video, I looked at variables, types of variables and hypothesis. In this particular video, I am going to look at sampling and different types of sampling methods. Sampling is one of the most important portion of this unit because every year at least one question out of five come from sampling. So make sure you have proper command over this topic so that you get that question right. Apart from that, in the research aptitude series, there is a very important topic called steps in research process. I am going to talk about steps in detail in my next video but for now if you really want to know about steps in research process, then I would request you to go to my YouTube channel and type steps in research process. You will get my video where I have discussed the steps in research process in detail. So let us begin by looking at sampling and let us also find out why sampling is important. So whenever you are doing a research or you are carrying an experiment, in that case you need to collect data from a group of people. Now this group of people can be as large as the entire country. For example, I want to conduct a research showing how many people are taller than six feet in India. In order to do this research, I need to collect data from 135 crore people who are in India. Is it possible? Do you think that's feasible? No, it's not. I cannot go to all those 135 crore people and note down their heights. So what I do in order to make my research simpler is that out of this 135 crore people, I randomly choose 1000 people. I note down the height of these 1000 people and then I conduct my research on them and whatever be the result, I generalize it on 135 crore people. So this group of 135 crore people are known as population whereas the sample which I select from this group is known as the sample of my research. So the research that you are doing on the people in your research is a part of the population and among the population, the people who conduct research on the people is called sample. And what happens when we do sampling? We kind of ease down our research process. And do you think sampling is only done in case we are conducting a research or carrying out an experiment? No. Even in our day to day life, there are instances where we do sampling. For example, if you go and you cook a meal for your mother and you are cooking a kind of vegetable, so you might find that you have to check whether the vegetable is properly cooked or not. So you are going to take a piece of the vegetable and you are going to taste it. Now what are you doing? You are actually selecting a sample rather than tasting each and every piece in that cooked box. You are only checking two or three pieces and on the basis of that you conclude whether the vegetable is properly cooked or not. This is exactly what the researchers do when they have a large population and they cannot go and take the data from each of them. They select a few people from them and then they conduct research on those people. When it comes to sampling, there are two kinds of sampling methods available in the market. The first one is called probability sampling and the second one is called non-probability sampling. Now probability as we all know is about the fact that every person or every item in that group has an equal chance of getting selected. For example, if I throw a dice and I ask you that what is the probability of getting four in the dice? So the probability would be one by six. That means each and every number on the dice that is one, two, three, four, five and six will have equal chances of being selected. So the same case happens in the case of probability sampling. So probability sampling is a kind of sampling method where each candidate in the population has equal chance of getting selected. For example, if I want to conduct a research on a group of people in my class, now I don't want to take all of them into my research, I just want to take 10 students out of 100 in my research. So what I do? I give numbers one to 100 to each and every student present in the class. Now by using a random number selector, I choose any 10 numbers. For example number 18, 27, 35 and so on so forth. So I choose 10 numbers and the people who had those 10 numbers, they are selected and are a part of my research. Lottery method is one of the most common probability sampling method because what happens in lottery method? In lottery method, every person has equal chance of getting a lottery. There are different types of probability sampling methods like simple random sampling, cluster sampling, stratified and so on so forth. So all of them are kind of based on the same idea that the number of people who are getting selected from each of them would be same. So that's about probability sampling. Let us move on and look at non-probability sampling. Now we'll have to look at the next kind of sampling method which is non-probability sampling. Now in non-probability sampling as the name suggests, participants are chosen in non-random ways. So every participant will not have an equal chance to get selected in the research. Let me give you a very simple example. So there's this research scholar Kiara. She wants to know people's opinion about LGBTQ, that's her research topic. Now she goes to a mall which is near to her house on one fine day and she asks people who are in that mall on that particular day about their views on LGBTQ. Now this kind of method of choosing sample and collecting data is known as convenient sampling which is a part of non-probability sampling because what is happening? Kiara is choosing the research participants based on her convenience. If you want Kiara to go through probability sampling in that case, she had to select people randomly from the entire India. So it's not like she will just go to a mall and collect data from all the people in that place. She will have to give random numbers to all the people in India and then she has to select few of them based on randomization or lottery. But she's not doing that because it is a tiresome task. If a person from Chennai becomes her sample, then how is she going to go and talk to him about the LGBTQ? So what she does is that she goes to a mall and she takes all the people opinions and views about LGBTQ. A similar kind of thing is done by the research scholars who are studying in a particular university. So if they want to conduct a research, then they take people studying in that university as the sample and they conduct research on them because that is very convenient for them. Apart from that, there are quota sampling and snowball sampling which are another prominent methods of non-probability sampling. But due to time crunch, I'm not going to talk about them in detail. But I would like you to know that all these topics are covered in detail in our online course. So if you really wish to study UGC-NET paper one in detail, you can join our online course for the same. So that's it from my side for this topic. I'll meet you very soon in the next video lecture. Till the time I meet next, happy learning, keep loving literature and stay tuned to arpathakarwa.com