Concept

Simple Random Sample

In a simple random sample, each member of a population is equally likely to be selected as part of the sample. Consider an example where a researcher performs the following procedure. |c| There are $20$ people, each assigned a unique number, who are surveyed. Of those $20$ people, $4$ need to be randomly selected as a sample. The researcher writes each unique number on a paper and places them in a bag.The researcher then blindly selects $4$ papers out of the bag.

The researcher's way of choosing a sample means that each participant is equally likely to be selected as part of the sample. The following applet shows a generated example of simple random samples.

Generate a random sample

To generate a simple random sample, each member of a population can be assigned a unique ID — for example, a whole number. Then, a random number generator can be used to generate IDs until the desired sample size is satisfied.

Extra

Biased or Unbiased Sampling
A simple random sample is an unbiased sample because it involves selecting members from a population randomly, guaranteeing that each member of the population has an equal chance of being included. This is usually representative as it tends to have the same characteristics as the population. 2 &Unbiased Sampling:&& Members of a population are selected randomly. &Biased Sampling:&& Members of a population are hand chosen, for example. An example of biased surveying would be a coach who asks only their favorite players about the effectiveness of their team's strategy. Just imagine if only the stars of the team are allowed to give their opinion to the coach. However, other instances might call for biased sampling such as a study about how Olympic athletes perform under pressure.

Exercises
Edit Lesson