name: "idl_env", dfpSlots['rightslot2'] = googletag.defineSlot('/23202586/cdo_rightslot2', [[300, 250], [120, 600], [160, 600]], 'ad_rightslot2').defineSizeMapping(mapping_rightslot2).setTargeting('sri', '0').setTargeting('vp', 'mid').setTargeting('hp', 'right').addService(googletag.pubads()); { bidder: 'appnexus', params: { placementId: '11654157' }}, Gendrift gehört wie Variabilität, Selektion und Isolation zu den Triebkräften der Evolution, den Evolutionsfaktoren. iasLog("exclusion label : wprod"); name: "unifiedId", As the term suggests, an observational study observes the real world as opposed to creating a controlled experiment.They are often conducted when an experiment would be unethical. { bidder: 'appnexus', params: { placementId: '11654156' }}, }, { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_MidArticle' }}, ga('require', 'displayfeatures'); Improve your vocabulary with English Vocabulary in Use from Cambridge.Learn the words you need to communicate with confidence. The difference between a bureaucracy's enactment of a law and the legislature's intent is called bureaucratic drift. { bidder: 'ix', params: { siteId: '555365', size: [300, 250] }}, storage: { type: "cookie", googletag.pubads().setTargeting("sfr", "cdo_dict_english"); { bidder: 'ix', params: { siteId: '555365', size: [120, 600] }}, storage: { Random Walk mit Drift Xt = d + Xt–1 + εt. var mapping_rightslot2 = googletag.sizeMapping().addSize([746, 0], [[300, 250], [120, 600], [160, 600]]).addSize([0, 0], []).build(); { bidder: 'ix', params: { siteId: '195451', size: [300, 250] }}, { bidder: 'onemobile', params: { dcn: '8a969411017171829a5c82bb4deb000b', pos: 'cdo_rightslot2_flex' }}, 'max': 8, },{ { bidder: 'sovrn', params: { tagid: '387233' }}, {code: 'ad_topslot_b', pubstack: { adUnitName: 'cdo_topslot', adUnitPath: '/23202586/cdo_topslot' }, mediaTypes: { banner: { sizes: [[728, 90]] } }, type: "html5", { bidder: 'pubmatic', params: { publisherId: '158679', adSlot: 'cdo_topslot' }}]}, { bidder: 'ix', params: { siteId: '195451', size: [300, 50] }}, bids: [{ bidder: 'rubicon', params: { accountId: '17282', siteId: '162036', zoneId: '1666926', position: 'btf' }}, 'buckets': [{ { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_rightslot' }}, var pbAdUnits = getPrebidSlots(curResolution); { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_MidArticle' }}, { bidder: 'appnexus', params: { placementId: '11653860' }}, { bidder: 'ix', params: { siteId: '555365', size: [160, 600] }}, { bidder: 'openx', params: { unit: '539971081', delDomain: 'idm-d.openx.net' }}, See more. {code: 'ad_btmslot_a', pubstack: { adUnitName: 'cdo_btmslot', adUnitPath: '/23202586/cdo_btmslot' }, mediaTypes: { banner: { sizes: [[300, 250]] } }, bids: [{ bidder: 'rubicon', params: { accountId: '17282', siteId: '162050', zoneId: '776358', position: 'atf' }}, 'max': 3, expires: 365 By simply looking at the subject and drawing what is presented to the eye, the art student gains solid perceptual skills and hand-eye coordination, as well as eliminating flawed preconceptions about the appearance of objects. { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_rightslot2' }}, The power or faculty of observing. { bidder: 'openx', params: { unit: '539971081', delDomain: 'idm-d.openx.net' }}, bids: [{ bidder: 'rubicon', params: { accountId: '17282', siteId: '162036', zoneId: '776130', position: 'btf' }}, { bidder: 'ix', params: { siteId: '195467', size: [300, 250] }}, { bidder: 'ix', params: { siteId: '555365', size: [160, 600] }}, { bidder: 'ix', params: { siteId: '195451', size: [300, 250] }}, googletag.pubads().setTargeting("cdo_tc", "resp"); { bidder: 'appnexus', params: { placementId: '19042093' }}, The volume of blood pumped by the heart in one minute. { bidder: 'ix', params: { siteId: '555365', size: [120, 600] }}, { bidder: 'ix', params: { siteId: '555365', size: [300, 250] }}, googletag.cmd.push(function() { { bidder: 'appnexus', params: { placementId: '11654208' }}, Psychology Definition of OBSERVER DRIFT: gradual step-by-step alterations over time in the observations and documenting of observations made by a specific viewer. { bidder: 'pubmatic', params: { publisherId: '158679', adSlot: 'cdo_rightslot2' }}]}]; dfpSlots['rightslot'] = googletag.defineSlot('/23202586/cdo_rightslot', [[300, 250]], 'ad_rightslot').defineSizeMapping(mapping_rightslot).setTargeting('sri', '0').setTargeting('vp', 'mid').setTargeting('hp', 'right').addService(googletag.pubads()); { bidder: 'openx', params: { unit: '539971063', delDomain: 'idm-d.openx.net' }}, { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_btmslot' }}, The definition of talent management with an example process. }, iasLog("criterion : cdo_tc = resp"); The definition of hospitality industry with examples. The definition of empirical evidence with examples. A record of the examiner’s observations is kept for later interpretation. In survey-type situations, these errors can be mistakes in the collection of data, including both the incorrect recording of a response and the correct recording of a respondent's inaccurate response. { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_btmslot' }}, The definition of random error with examples. { bidder: 'sovrn', params: { tagid: '446382' }}, storage: { googletag.pubads().setTargeting("cdo_ptl", "entry-lcp"); Instead, a rigorous test of rating drift must check whether firms in a specific rating class exhibit the same rating behavior regardless of whether they obtained their current rating through an upgrade of a downgrade. b. 'min': 31, { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_HDX' }}, name: "pbjs-unifiedid", { bidder: 'appnexus', params: { placementId: '11653860' }}, "sign-up": "https://dictionary.cambridge.org/auth/signup?rid=READER_ID", bids: [{ bidder: 'rubicon', params: { accountId: '17282', siteId: '162036', zoneId: '1666926', position: 'btf' }}, The 7 types of process with examples of each. { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_SR' }}, An overview of precision with detailed examples. name: "criteo" document.head.appendChild(btScript); Browse our dictionary apps today and ensure you are never again lost for words. { bidder: 'sovrn', params: { tagid: '387232' }}, It takes place by watching the behavior of others. {code: 'ad_topslot_b', pubstack: { adUnitName: 'cdo_topslot', adUnitPath: '/23202586/cdo_topslot' }, mediaTypes: { banner: { sizes: [[728, 90]] } }, { bidder: 'ix', params: { siteId: '195451', size: [320, 50] }}, bids: [{ bidder: 'rubicon', params: { accountId: '17282', siteId: '162050', zoneId: '776358', position: 'atf' }}, { bidder: 'ix', params: { siteId: '194852', size: [300, 250] }}, Observational drawing is exactly what it sounds like: drawing via observation. syncDelay: 3000 {code: 'ad_leftslot', pubstack: { adUnitName: 'cdo_leftslot', adUnitPath: '/23202586/cdo_leftslot' }, mediaTypes: { banner: { sizes: [[120, 600], [160, 600], [300, 600]] } }, var pbTabletSlots = [ { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_Billboard' }}, den Drift d ≠ 0 ergänzt, so ergibt sich ein sog. var dfpSlots = {}; Definition, Rechtschreibung, Synonyme und Grammatik von 'Drift' auf Duden online nachschlagen. { bidder: 'onemobile', params: { dcn: '8a969411017171829a5c82bb4deb000b', pos: 'cdo_btmslot_300x250' }}, partner: "uarus31" Als Beobachtungsstudie bezeichnet man meistens eine patientenbezogene Datenerhebung im Gesundheitsbereich, z. name: "identityLink", {code: 'ad_btmslot_a', pubstack: { adUnitName: 'cdo_btmslot', adUnitPath: '/23202586/cdo_btmslot' }, mediaTypes: { banner: { sizes: [[300, 250]] } }, { bidder: 'ix', params: { siteId: '195465', size: [300, 250] }}, { bidder: 'onemobile', params: { dcn: '8a969411017171829a5c82bb4deb000b', pos: 'cdo_topslot_728x90' }}, },{ Observational definition, of, relating to, or founded on observation, especially founded on observation rather than experiment. "loggedIn": false if(refreshConfig.enabled == true) addPrebidAdUnits(pbAdUnits); Visit our, Copyright 2002-2021 Simplicable. { bidder: 'pubmatic', params: { publisherId: '158679', adSlot: 'cdo_leftslot' }}]}, The definition of systematic error with examples. { bidder: 'ix', params: { siteId: '194852', size: [300, 250] }}, userIds: [{ The most popular articles on Simplicable in the past day. Before we take a dive into the deep end, let’s get started by first defining the key terms related to cardiac drift. All Rights Reserved. Metrologie.Die Messabweichung ist definiert als eine Differenz zwischen Messwert und Referenzwert. observational definition: 1. involving watching someone or something carefully and closely, in order to learn something: 2…. { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_btmslot' }}, 'cap': true definition of a ‘non-interventional trial’ within Directive 2001/20/EC3 (also known as the Clinical Trials Directive) and how this definition is being interpreted differently amongst EU Member States and National Competent Authorities, leading to difficulties in the conduct of such trials (particularly when conducted in more than one Member State). { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_SR' }}, { bidder: 'onemobile', params: { dcn: '8a969411017171829a5c82bb4deb000b', pos: 'cdo_topslot_728x90' }}, February 1, 2021. "sign-in": "https://dictionary.cambridge.org/auth/signin?rid=READER_ID", Usage explanations of natural written and spoken English, 0 && stateHdr.searchDesk ? { bidder: 'onemobile', params: { dcn: '8a969411017171829a5c82bb4deb000b', pos: 'cdo_btmslot_300x250' }}, { bidder: 'appnexus', params: { placementId: '11654208' }}, Cookies help us deliver our site. iasLog("criterion : sfr = cdo_dict_english"); Add the power of Cambridge Dictionary to your website using our free search box widgets. googletag.pubads().disableInitialLoad(); 'min': 8.50, }, A reasonably complete overview of research & development techniques. { bidder: 'ix', params: { siteId: '195467', size: [320, 50] }}, { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_rightslot' }}, googletag.pubads().addEventListener('slotRenderEnded', function(event) { if (!event.isEmpty && event.slot.renderCallback) { event.slot.renderCallback(event); } }); DEFINING PROCEDURAL DRIFT Procedural drift is a problem that is not always apparent at first glance. "authorizationTimeout": 10000 { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_Billboard' }}, { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_rightslot2' }}, { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_btmslot' }}, { bidder: 'onemobile', params: { dcn: '8a969411017171829a5c82bb4deb000b', pos: 'cdo_btmslot_300x250' }}, googletag.pubads().set("page_url", "https://dictionary.cambridge.org/dictionary/english/observational"); { bidder: 'ix', params: { siteId: '195466', size: [728, 90] }}, I have trained numerous observers over the last three years, and I have noticed that sometimes we forget to use our CLASS lens when we are observing people that we know. { bidder: 'openx', params: { unit: '539971063', delDomain: 'idm-d.openx.net' }}, 'increment': 0.05, Research based on observation of the real world whereby variables are beyond the control of researchers. { bidder: 'openx', params: { unit: '539971080', delDomain: 'idm-d.openx.net' }}, { bidder: 'openx', params: { unit: '539971065', delDomain: 'idm-d.openx.net' }}, observationally synonyms, observationally pronunciation, observationally translation, English dictionary definition of observationally. Learn more. googletag.pubads().setTargeting("cdo_dc", "english"); process of collecting data about a group of objects to draw conclusions about populations of those objects googletag.pubads().setTargeting("cdo_pt", "entry"); { bidder: 'sovrn', params: { tagid: '346698' }}, Price includes VAT for USA. (Die Bezeichnung Messfehler wird in der gegenwärtigen Norm nicht mehr verwendet, da nicht klar definiert ist, ob damit die Messabweichung, die Messunsicherheit oder gar ein grober Fehler gemeint ist, siehe Messfehler). { bidder: 'pubmatic', params: { publisherId: '158679', adSlot: 'cdo_rightslot2' }}]}]; Reproduction of materials found on this site, in any form, without explicit permission is prohibited. "sign-out": "https://dictionary.cambridge.org/auth/signout?rid=READER_ID" name: "pubCommonId", The definition of natural experiment with examples. It can occur in a number of different ways and does not require reinforcement in order to be successful. }; Gendrift bei Wortbedeutung.info: Bedeutung, Definition, Synonyme, Übersetzung, Rechtschreibung, Beispiele. { bidder: 'sovrn', params: { tagid: '705055' }}, }, dfpSlots['houseslot_a'] = googletag.defineSlot('/2863368/houseslot', [300, 250], 'ad_houseslot_a').defineSizeMapping(mapping_houseslot_a).setTargeting('sri', '0').setTargeting('vp', 'mid').setTargeting('hp', 'right').setCategoryExclusion('house').addService(googletag.pubads()); Drift happens to people who have passed the reliability test, but over time they start scoring subjective ly—they let their biases affect the data. 'increment': 0.5, {code: 'ad_topslot_a', pubstack: { adUnitName: 'cdo_topslot', adUnitPath: '/23202586/cdo_topslot' }, mediaTypes: { banner: { sizes: [[300, 50], [320, 50], [320, 100]] } }, ga('set', 'dimension2', "entryex"); Their system proves fewer program transformations as equalities, requiring instead the more difficult notion of, Specifically, it is likely that experimental data will be needed to replicate and extend the current findings based here on, Examining the role of parental frightened/frightening subtypes in predicting disorganized attachment within a brief, As soil nitrogen concentrations were not reported, these, In addition, with such an approach, critics can legitimately question the exclusion of nonrandomized or, Phase-space holes also have less spectacular, Naturalistic studies of older children could give a better point of comparison with the, We first prove the adequacy with respect to the. if(pl_p) priceGranularity: customGranularity, googletag.pubads().setCategoryExclusion('lcp').setCategoryExclusion('resp').setCategoryExclusion('wprod'); Sports scientist, marathon runner and Ironman finisher Benjamin Garcia gives us the nitty-gritty. { bidder: 'openx', params: { unit: '539971066', delDomain: 'idm-d.openx.net' }}, iasLog("criterion : cdo_pt = entry"); Launenhafte Viren: Gen-Drift und Gen-Shift. var pbMobileHrSlots = [ window.ga=window.ga||function(){(ga.q=ga.q||[]).push(arguments)};ga.l=+new Date; { bidder: 'sovrn', params: { tagid: '705055' }}, { bidder: 'pubmatic', params: { publisherId: '158679', adSlot: 'cdo_btmslot' }}]}, One popular exercise in observational drawing is contour drawing. { bidder: 'openx', params: { unit: '539971066', delDomain: 'idm-d.openx.net' }}, "error": true, expires: 60 1 Discover the basics of observational drawing as well as advanced applications.. 2 Learn how to incorporate observational drawing methods and techniques into a variety of lessons.. 3 Use these strategies and techniques with any student skill level.. Observational drawing is a vital part of any drawing curriculum. Click on the arrows to change the translation direction. }, bids: [{ bidder: 'rubicon', params: { accountId: '17282', siteId: '162036', zoneId: '776156', position: 'atf' }}, Observational assessments involve obtaining evaluative information through direct observation. { bidder: 'appnexus', params: { placementId: '11654157' }}, G. A. Smith 1 The Behavior Analyst volume 9, pages 127 – 128 (1986)Cite this article. { bidder: 'openx', params: { unit: '541042770', delDomain: 'idm-d.openx.net' }}, The word in the example sentence does not match the entry word. { bidder: 'sovrn', params: { tagid: '387232' }}, { bidder: 'sovrn', params: { tagid: '346688' }}, Das ist mit dem Gendrift nicht gemeint.. Stattdessen bedeutet der Gendrift, dass, sobald sich ein Individuum oder eine kleine Menge an Individuen von ihrer Ursprungspopulation abtrennt, sich die abgetrennte Menge durch ihren individuellen Genpool von der Ursprungspopulation unterscheidet. { bidder: 'sovrn', params: { tagid: '387233' }}, . Lexikon Online ᐅDrift: Konstante, die ein nicht stationärer (Stationarität) stochastischer Prozess enthält. } bids: [{ bidder: 'rubicon', params: { accountId: '17282', siteId: '162036', zoneId: '776130', position: 'btf' }}, What is Cardiac output? Subscribe to journal. { bidder: 'onemobile', params: { dcn: '8a9690ab01717182962182bb50ce0007', pos: 'cdo_btmslot_mobile_flex' }}, The definition of original research with examples. Sie werden meist als rein explorative Studien angelegt, zum Generieren von Hypothesen, oder auch eingeschränkt zum Abschätzen der Gültigkeit von Hypothesen. { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_SR' }}, bids: [{ bidder: 'rubicon', params: { accountId: '17282', siteId: '162050', zoneId: '776336', position: 'btf' }}, 'cap': true ga('create', 'UA-31379-3',{cookieDomain:'dictionary.cambridge.org',siteSpeedSampleRate: 10}); googletag.pubads().setTargeting("cdo_pc", "dictionary"); { bidder: 'onemobile', params: { dcn: '8a969411017171829a5c82bb4deb000b', pos: 'cdo_rightslot2_flex' }}, pbjsCfg = { The common types of random assignment for experiments. var pbDesktopSlots = [ Definition of observation (Entry 2 of 2) : designed for use in viewing something (such as scenery) or in making observations an observation tower the observation platform Other Words from observation … { bidder: 'pubmatic', params: { publisherId: '158679', adSlot: 'cdo_btmslot' }}]}, },{ googletag.cmd = googletag.cmd || []; { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_leftslot' }}, iasLog("criterion : cdo_pc = dictionary"); Define observationally. var googletag = googletag || {}; The definition of negative control with examples. expires: 365 bids: [{ bidder: 'rubicon', params: { accountId: '17282', siteId: '162036', zoneId: '776130', position: 'btf' }}, iframe: { },{ Although observational assessments could potentially be used in any domain, they most often are used for behavior, social-emotional functioning, and language. iasLog("criterion : cdo_t = senses-and-sounds"); bids: [{ bidder: 'rubicon', params: { accountId: '17282', siteId: '162036', zoneId: '776160', position: 'atf' }}, { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_rightslot2' }}, { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_btmslot' }}, 1 Definition. { bidder: 'sovrn', params: { tagid: '346693' }}, dfpSlots['topslot_a'] = googletag.defineSlot('/23202586/cdo_topslot', [], 'ad_topslot_a').defineSizeMapping(mapping_topslot_a).setTargeting('sri', '0').setTargeting('vp', 'top').setTargeting('hp', 'center').addService(googletag.pubads()); (Chatting about the weekend), Clear explanations of natural written and spoken English. Eine gewisse Bedeutung kommt ihr auch in Gründerpopulationen zu. bids: [{ bidder: 'rubicon', params: { accountId: '17282', siteId: '162036', zoneId: '1666926', position: 'btf' }}, bids: [{ bidder: 'rubicon', params: { accountId: '17282', siteId: '162036', zoneId: '776160', position: 'atf' }}, iasLog("criterion : cdo_ptl = entry-lcp"); Man sagt dann auch, der Random Walk besitzt einen stochastischen Trend. "authorizationFallbackResponse": { iasLog("setting page_url: - https://dictionary.cambridge.org/dictionary/english/observational"); },{ { bidder: 'sovrn', params: { tagid: '387232' }}, var mapping_houseslot_b = googletag.sizeMapping().addSize([963, 0], []).addSize([0, 0], [300, 250]).build(); The act of observing: observations of a rare bird. googletag.pubads().setTargeting("cdo_c", ["science_geographic_locales"]); { bidder: 'criteo', params: { networkId: 7100, publisherSubId: 'cdo_topslot' }}, Observational learning, method of learning that consists of observing and modeling another individual’s behavior, attitudes, or emotional expressions.Although it is commonly believed that the observer will copy the model, American psychologist Albert Bandura stressed that individuals may simply learn from the behavior rather than imitate it. {code: 'ad_btmslot_a', pubstack: { adUnitName: 'cdo_btmslot', adUnitPath: '/23202586/cdo_btmslot' }, mediaTypes: { banner: { sizes: [[300, 250], [320, 50], [300, 50]] } }, It can exist throughout your organization, and it represents a real threat to the safety of your operations and employees. The definition of positive control with examples. ein Random Walk Xt = Xt–1 + εt, um eine Konstante bzw. { bidder: 'ix', params: { siteId: '195464', size: [120, 600] }}, The definition of observational study with examples. { bidder: 'sovrn', params: { tagid: '346693' }}, { bidder: 'openx', params: { unit: '539971079', delDomain: 'idm-d.openx.net' }}, { bidder: 'ix', params: { siteId: '195464', size: [120, 600] }}, {code: 'ad_rightslot2', pubstack: { adUnitName: 'cdo_rightslot2', adUnitPath: '/23202586/cdo_rightslot2' }, mediaTypes: { banner: { sizes: [[300, 250], [120, 600], [160, 600]] } }, googletag.pubads().setTargeting("cdo_t", "senses-and-sounds"); { bidder: 'triplelift', params: { inventoryCode: 'Cambridge_HDX' }}, Wörterbuch der deutschen Sprache. googletag.pubads().setTargeting("cdo_ei", "observational"); pbjs.que = pbjs.que || []; { bidder: 'ix', params: { siteId: '194852', size: [300, 250] }}, googletag.pubads().enableSingleRequest(); { bidder: 'appnexus', params: { placementId: '11653860' }}, Observational Drawing. iasLog("exclusion label : lcp"); { bidder: 'onemobile', params: { dcn: '8a9690ab01717182962182bb50ce0007', pos: 'cdo_topslot_mobile_flex' }}, { bidder: 'ix', params: { siteId: '195467', size: [300, 50] }}, bidders: '*', { bidder: 'sovrn', params: { tagid: '346693' }}, The reason procedural drift can go unseen for so long is that is has a way of creeping into an organization. bids: [{ bidder: 'rubicon', params: { accountId: '17282', siteId: '162036', zoneId: '776140', position: 'atf' }}, Observational learning is sometimes also known as: Shaping; Modeling; Vicarious reinforcement; Observational learning is a form of social learning. { bidder: 'appnexus', params: { placementId: '11654149' }}, var pbMobileLrSlots = [ { bidder: 'sovrn', params: { tagid: '446381' }}, Wird z.B. The definition of explanatory power with examples. drift Bedeutung, Definition drift: 1. to move slowly, especially as a result of outside forces, with no control over direction: 2…. var pbjs = pbjs || {}; Metrics details. }); { bidder: 'openx', params: { unit: '539971079', delDomain: 'idm-d.openx.net' }}, { bidder: 'sovrn', params: { tagid: '705055' }}, pbjs.setConfig(pbjsCfg); { bidder: 'sovrn', params: { tagid: '446382' }}, pid: '94' // FIXME: (temporary) - send ad requests only if PlusPopup is not shown filterSettings: { {code: 'ad_topslot_b', pubstack: { adUnitName: 'cdo_topslot', adUnitPath: '/23202586/cdo_topslot' }, mediaTypes: { banner: { sizes: [[728, 90]] } }, Wann ist ein Grippe-Virus erfolgreich? }] What is cardiac drift and how does it affect heart rate training? var btScript = document.createElement('script'); Es ,,fließen", bzw. What is Stroke volume? { bidder: 'pubmatic', params: { publisherId: '158679', adSlot: 'cdo_topslot' }}]}, name: "_pubcid", drift = Strömung], Alleldrift, Sewall-Wright-Effekt, die zufällige Veränderung der Allelhäufigkeit (Allelenfrequenz) in kleinen Populationen; wird vermutlich als Evolutionsfaktor nur in verhältnismäßig kleinen Populationen wirksam. Der Begriff Gendrift beschreibt eine Veränderung der Allelfrequenz in einem Genpool einer Population durch ein Zufallsereignis, zum Beispiel eine Naturkatastrophe, Vulkanausbrüche, Plattentektonik oder eine spezifische Krankheit.. 2 Bedeutung.