TY - JOUR A1 - Post, Julia C. A1 - Class, Fabian A1 - Kohler, Ulrich T1 - Unit nonresponse biases in estimates of SARS-CoV-2 prevalence JF - Survey research methods N2 - Since COVID-19 became a pandemic, many studies are being conducted to get a better understanding of the disease itself and its spread. One crucial indicator is the prevalence of SARS-CoV-2 infections. Since this measure is an important foundation for political decisions, its estimate must be reliable and unbiased. This paper presents reasons for biases in prevalence estimates due to unit nonresponse in typical studies. Since it is difficult to avoid bias in situations with mostly unknown nonresponse mechanisms, we propose the maximum amount of bias as one measure to assess the uncertainty due to nonresponse. An interactive web application is presented that calculates the limits of such a conservative unit nonresponse confidence interval (CUNCI). KW - COVID-19 KW - prevalence KW - probability samples KW - unit nonresponse KW - conservative confidence limits KW - nonresponse bias Y1 - 2020 U6 - https://doi.org/10.18148/srm/2020.v14i2.7755 SN - 1864-3361 VL - 14 IS - 2 SP - 115 EP - 121 PB - European Survey Research Association CY - Duisburg ER - TY - JOUR A1 - Kohler, Ulrich A1 - Post, Julia C. T1 - Welcher Zweck heiligt die Mittel? T1 - Which Ends Justify the Means? BT - Bemerkungen zur Repräsentativitätsdebatte in der Umfrageforschung BT - Comments on the Usability of Non-Probability Samples for Opinion Polls JF - Zeitschrift für Soziologie N2 - Im Vergleich zu Umfragen an Wahrscheinlichkeitsstichproben bieten Umfragen an Access-Panels, die auf Nicht-Wahrscheinlichkeitsstichproben basieren, unbestreitbare wirtschaftliche Vorteile. Diese Vorteile gehen jedoch mit unvermeidbaren Qualitätseinbußen einher, die auch dann bestehen bleiben, wenn Erstere sehr niedrige Responseraten haben. Daher müssen die wirtschaftlichen Vorteile und die methodischen Einschränkungen gegeneinander abgewogen werden. Es wird argumentiert, dass diese Abwägung anhand normativer Festlegungen erfolgen muss. Unter Anwendung der hier vorgeschlagenen Maßstäbe kommt der Beitrag zu dem Schluss, dass die Qualitätsansprüche an über Massenmedien verbreitete Meinungsumfragen höher sein sollten als für rein (sozial)wissenschaftliche Zwecke. N2 - Compared with surveying respondents of a probability sample, surveying members of a self-selective custom online panel offers indisputable economic advantages. However, these advantages come with an unavoidable drop in quality. This disadvantage holds true even in comparison to probability sampling surveys with very low response rates. Therefore, it is necessary to balance the economic advantages against the methodological limitations. We argue that this consideration needs to be done according to normative determinations. Using the criteria proposed in this article, we conclude that public opinion research distributed through mass media should have higher quality standards than research with solely scientific purposes. KW - Umfragen KW - Meinungsumfragen KW - Repräsentativität KW - Wahrscheinlichkeitsstichproben KW - Nicht-Wahrscheinlichkeitsstichproben KW - Unit-Nonresponse KW - Selbstselektion KW - Responseraten KW - Online-Access-Panel KW - Surveys KW - Public Opinion Research KW - Polls KW - Representativeness KW - Survey Inference KW - Probability Sampling KW - Non-probability Sampling KW - Unit Nonresponse KW - Self-selection KW - Response Rates KW - Custom Online Panel Y1 - 2023 U6 - https://doi.org/10.1515/zfsoz-2023-2001 SN - 2366-0325 SN - 0340-1804 VL - 52 IS - 1 SP - 67 EP - 88 PB - de Gruyter CY - Oldenburg ER - TY - JOUR A1 - Kohler, Ulrich A1 - Post, Julia C. T1 - Pulp Science? BT - zur Berichterstattung über Meinungsforschung in den Massenmedien JF - Gesellschaft, Wirtschaft, Politik : GWP : Sozialwissenschaften für politische Bildung Y1 - 2023 U6 - https://doi.org/10.3224/gwp.v72i4.09 SN - 2196-1654 SN - 1619-6910 VL - 72 IS - 4 SP - 475 EP - 483 PB - Budrich CY - Leverkusen ER -