Browse Definitions :
Definition

sample

A sample, in the context of scientific research and statistics, is a representative subset of a population.  

It's often impractical – if not impossible – to access an entire population for research or data collection. A survey involving the sleep habits of university students, for example, would be hard-pressed to collect data from all current students, and an experiment researching the effects of overpopulation in Norway rats could never include all the specimens in existence. 

To get around that problem, researchers access a sample group. Characteristics of the sample should match those of the population so that the outcome of an experiment or survey conducted on a sample would be replicable if it were possible to research the whole population. 

In probability-based sampling, all members of a population are equally likely to be selected, which helps ensure that the sample will be representative of the population. Researchers employ one of several random sampling methods: 

Simple random sampling involves using software to randomly select subjects from the whole population. 

Stratified random sampling involves creating subsets of the population based on some common factor and then randomly selecting samples from each group.  

Cluster sampling involves breaking the population into separate groups, randomly selecting a subset of the groups from the population and using all members that subset.  

Nonprobability-based methods include: 

Convenience sampling, which involves simply collecting data from some group that is available to the researchers. 

Purposive sampling, which involves defining subject criteria and then seeking out subjects that match that criteria.  

Quota sampling, which involves defining some criteria for subjects that you want included in a certain percentage of samples to ensure that specific subgroups are represented.  

Although nonprobability-based sampling does not ensure validity as well, it is typically simpler to conduct. In any case, however, no sampling method is infallible and researchers need to be aware of the sampling errors that can invalidate their efforts. 

This was last updated in February 2018

Continue Reading About sample

SearchCompliance
  • OPSEC (operations security)

    OPSEC (operations security) is a security and risk management process and strategy that classifies information, then determines ...

  • smart contract

    A smart contract is a decentralized application that executes business logic in response to events.

  • compliance risk

    Compliance risk is an organization's potential exposure to legal penalties, financial forfeiture and material loss, resulting ...

SearchSecurity
  • threat modeling

    Threat modeling is a procedure for optimizing application, system or business process security by identifying objectives and ...

  • distributed denial-of-service (DDoS) attack

    A distributed denial-of-service (DDoS) attack is one in which multiple compromised computer systems attack a target, such as a ...

  • social engineering

    Social engineering is an attack vector that relies heavily on human interaction and often involves manipulating people into ...

SearchHealthIT
SearchDisasterRecovery
  • change control

    Change control is a systematic approach to managing all changes made to a product or system.

  • disaster recovery (DR)

    Disaster recovery (DR) is an organization's ability to respond to and recover from an event that affects business operations.

  • risk mitigation

    Risk mitigation is a strategy to prepare for and lessen the effects of threats faced by a business.

SearchStorage
  • bare-metal cloud

    Bare-metal cloud is a public cloud service that offers dedicated hardware resources without any installed operating systems or ...

  • race condition

    A race condition is an undesirable situation that occurs when a device or system attempts to perform two or more operations at ...

  • storage security

    Storage security is the group of parameters and settings that make storage resources available to authorized users and trusted ...

Close