@prefix skos: <http://www.w3.org/2004/02/skos/core#> .
@prefix isothes: <http://purl.org/iso25964/skos-thes#> .

<https://concepts.sagepub.com/social-science/concept/volunteer_effect>
  skos:definition "The volunteer effect is a form of selection bias, sometimes referred to as self-selection or volunteer bias. This phenomenon is based on the idea that individuals who volunteer to participate in epidemiological studies are different in some way from the target population that they have originated from. [Source: <a href=\"https://methods.sagepub.com/reference/encyc-of-epidemiology/n478.xml\" target=\"_blank\" data-id=\"to-srm\">Encyclopedia of Epidemiology; Volunteer Effect</a>]"@en ;
  skos:broader <https://concepts.sagepub.com/social-science/concept/statistics_and_research_methods> ;
  skos:prefLabel "volunteer effect"@en ;
  a skos:Concept .

<https://concepts.sagepub.com/social-science/concept/conceptgroup/methods>
  a skos:Collection, isothes:ConceptGroup ;
  skos:prefLabel "methods"@en ;
  skos:member <https://concepts.sagepub.com/social-science/concept/volunteer_effect> .

<https://concepts.sagepub.com/social-science/concept/statistics_and_research_methods>
  skos:prefLabel "statistics and research methods"@en ;
  a skos:Concept ;
  skos:narrower <https://concepts.sagepub.com/social-science/concept/volunteer_effect> .