What is a 'Simple Random Sample'
A simple random sample is a subset of a statistical population in which each member of the subset has an equal probability of being chosen. A simple random sample is meant to be an unbiased representation of a group. An example of a simple random sample would be a group of 25 employees chosen out of a hat from a company of 250 employees. In this case, the population is all 250 employees, and the sample is random because each employee has an equal chance of being chosen.
BREAKING DOWN 'Simple Random Sample'
A sampling error can occur with a simple random sample if the sample doesn't end up accurately reflecting the population it is supposed to represent. For example, in our simple random sample of 25 employees, it would be possible to draw 25 men even if the population consisted of 125 women and 125 men. For this reason, simple random sampling is more commonly used when the researcher knows little about the population. If the researcher knew more, it would be better to use a different sampling technique, such as stratified random sampling, which helps to account for the differences within the population (such as age, race or gender).

Sampling
A process used in statistical analysis in which a predetermined ... 
Systematic Sampling
A type of probability sampling method in which sample members ... 
Stratified Random Sampling
A method of sampling that involves the division of a population ... 
Sample
A subset containing the characteristics of a larger population. ... 
Sampling Error
A statistical error to which an analyst exposes a model simply ... 
Sampling Distribution
A probability distribution of a statistic obtained through a ...

Fundamental Analysis
Understanding the Simple Random Sample
A simple random sample is a subset of a statistical population in which each member of the subset has an equal probability of being chosen. 
Fundamental Analysis
How Does Sampling Work?
Sampling is a term used in statistics that describes methods of selecting a predefined representative number of data from a larger data population. 
Fundamental Analysis
What is a Representative Sample?
In statistics, a representative sample accurately represents the makeup of various subgroups in an entire data pool. 
Professionals
Sampling and Estimation
CFA Level 1  Sampling and Estimation sampling error, in depth information on confidence intervals and tdistributions 
Economics
What is Systematic Sampling?
Systematic sampling is similar to random sampling, but it uses a pattern for the selection of the sample. 
Investing
How to Use Stratified Random Sampling
Stratified random sampling is a technique best used with a sample population easily broken into distinct subgroups. Samples are then taken from each subgroup based on the ratio of the subgroupâ€™s ... 
Fundamental Analysis
Explaining Standard Error
Standard error is a statistical term that measures the accuracy with which a sample represents a population. 
Fundamental Analysis
Explaining the Central Limit Theorem
Central limit theorem is a fundamental concept in probability theory. 
Professionals
Interpreting Statistical Results
CFA Level 1  Test Statistics and Interpreting Results 
Professionals
Sampling Considerations
CFA Level 1  Sampling Considerations

What are the best selection methods for creating a simple random sample?
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What are the advantages of using a simple random sample to study a larger population?
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When is it better to use systematic over simple random sampling?
Learn when systematic sampling is better than simple random sampling, such as in the absence of data patterns and when there ... Read Answer >> 
What are the disadvantages of using a simple random sample to approximate a larger ...
Learn what a simple random sample is, how researchers use it as a statistical tool and the disadvantages it carries when ... Read Answer >> 
How do researchers ensure that a simple random sample is an accurate representation ...
Learn which methods researchers employ to ensure that a simple random sample best approximates the larger population being ... Read Answer >> 
What is the difference between a simple random sample and a stratified random sample?
Learn about the differences between simple random sampling and stratified random sampling, and learn about the advantages ... Read Answer >>