Speaker 1: Okay, my dear friends, now we are at the final stage of our topic today. How to calculate sample size? We know we can collect or we can select our sample based on probability or non-probability sampling method. But what number do we need to select? What would be the number of population which is optimum for our research? This is a well-debated question and I think I could not answer it in a very simple way because sampling size or sample size is rather depend on the method you are using for your research. For example, qualitative method have a different sampling strategy or sample size strategy. Quantitative methods have different and mixed method have different. So I will try to cover all these three different methods and their sampling size in another video because it is a huge topic and it needs a lot of time. But in today's lecture, I will give you a very simple criteria, a very simple formula to sample or to size or to calculate your sample size. Now remember, sampling procedure or sample size calculation, it depends on two major important parameters. The first one is your population. So estimations from your population, the first criteria and the second method or criteria is what type of test you are going to use on your statistical procedure. So sampling or sample size, you can calculate based on your population or your statistical procedures you are going to apply on your data. So these two are simple techniques. But as I mentioned, this is not a very simple method or simple debate. It has a lot of discussions. I will cover these discussions in upcoming videos. But here, let us discuss one method of sample size calculation to complete today's topic. So sample size calculation according to Craig's Morgan table. So you can use this formula to calculate your sample size. Remember, this is a very simple formula, but it looks a very difficult formula. But I will explain each of these components to you and then you will understand that the sampling method is very simple. For example, here X is 1.96. It is equivalent to your T value. If you are looking for 5% of confidence interval, it means that T would be 1.96. And this is the value you are going to use for X value. If you are using different confidence interval, this X value would be different based on the confidence interval or confidence level you are using for your data analysis. In normal cases, we use 95% as a standard. So that is why this is 1.96. This is X. So the P here is population portion. There are different debates available on this. Minimum can be 30%. But if you use 50% sample size in this formula, sample population proportion, in this formula if you assume 50%, it means that it will give you the maximum size of your sample. So that's why we use this 50% formula. And the D is degree of accuracy, which is equivalent to P. So P is 0.005. It means that it is 95% accurate. So only 5% chances of error. So this is D, degrees of accuracy. If you are using 1.96, you must need to use this 0.05, okay? And the next criteria is N, which is your number of population. So what is your estimated population, okay? So this is P. So here I give you some rough calculation. For example, my population is 150,000, more than 150,000. 1.96 is my T value and X value. And if you calculate all these values, you will see that you can get S is equal to 384, which is your sample size. So you can calculate your sample size based on this formula easily and accurately, okay? And if you want to use Morgan table, the Morgan table, if you search on the Google, you will find Morgan table is available. And I will try to put the link in description for the Morgan table also. So you can directly use your sample size calculation by Morgan table also. But it depends on so many factors which I displayed within this formula, okay? So you can use this sample size calculation formula for your basic sample size calculation. But remember, as I mentioned, sampling calculation is not a very simple topic. So we have to cover it in any other video where I will discuss what should be the optimum sample size based on your methods, quantitative and then the technique of statistical techniques or software you are going to use. Or if you are using qualitative method, what would be your sample size? And if you are using any other procedures, for example, mixed method or multi-method research, what would be the optimum number of samples you need to collect for your studies, okay? So this will be covered in next lecture, hopefully. Okay, with this, I hope so you understand the basic concept of sampling strategy where I discuss about different methods of sampling strategy or different methods of sample collection. And then we discuss the basic formula for sample size calculation. Thank you very much and have a very nice day and see you in the next video. Bye bye.