Even if a list is readily available, it may be challenging to gain access to that list.

In order to select a sample n of students from this population of 10,000 students, we could choose to use a simple random sample. These random numbers can either be found using random number tables or a computer program that generates these numbers for you.

In the case of human populations, to avoid potential bias in your sample, you will also need to try and ensure that an adequate proportion of your sample takes part in the research. One of the most convenient ways of creating a simple random sample is to use a random number table.

This powerpoint goes over the basics of simple random sampling, why we use it, how we use it, and provides a very basic example. But, like most studies, if you are only using each unit a maximum of one time, you will skip over that number and go onto the next. Select the first n numbers however many numbers are in your sample whose last X digits are between 0 and N.

The best way to do this is to close your eyes and point randomly onto the page.

Imagine the first three numbers from the random number table were: Looking at columns 2 and 3, the first entry is "10. Calculators with the capability to generate random numbers nearly always give a random uniform number between 0 and 1. We would select the 11 th , 9,292 nd and 2,001 st students from our list to be part of the sample. However, we could have also determined the sample size we needed using a sample size calculation , which is a particularly useful statistical tool.

If you just used 0. Read down the columns from the arbitrary starting point, accepting any integers in your range.

Repeat these steps for the remaining seven quadrats. We've just gotten three. And those 30 names that you pick, that would be your simple random sample and then you could measure their heights to estimate the average height for the population.

The basics , some of these populations will be expensive and time consuming to contact, even where a list is available. To log in and use all the features of Khan Academy, please enable JavaScript in your browser.

If you were actually carrying out this research, you would most likely have had to receive permission from Student Records or another department in the university to view a list of all students studying at the university. This packet introduces you to simple random sampling, a basic method of sampling. Creating a simple random sample To create a simple random sample, there are six steps: Video transcript - [Teacher] Let's say that your school has a population of 80 students in it.

Sampling methods.

Maybe it's just your grade. Try this out if you are having difficulty with this concept. Let's imagine that we choose a sample size of 200 students.

If you can't wait to jump all over these methods of using random numbers, go to Assignments in Blackboard and select the quiz called "Using random numbers.