Self-Selection Bias

Examples of Self-Selection Bias in the following topics:

• Sampling Bias

  • This section discusses various types of sampling biases including self-selection bias and survivorship bias.
  • Many of the admittedly "non-scientific" polls taken on television or web sites suffer greatly from self-selection bias.
  • A self-selection bias can result when the non-random component occurs after the potential subject has enlisted in the experiment.
  • He concluded that, in addition to the undercoverage described above, there was a nonresponse bias (a form of self-selection bias) such that those favoring Landon were more likely to return their survey than were those favoring Roosevelt.
  • Therefore, there is a bias toward selecting better-performing funds.

• The Problems with Polls

  • Problems with polls typically stem either from issues with the methodology that bias the sample or the responses that cause the bias.
  • Because of this selection bias, the characteristics of those who agree to be interviewed may be markedly different from those who decline.
  • Selection bias occurs when some units have a differing probability of selection that is unaccounted for by the researcher.
  • In statistics, self-selection bias arises in any situation in which individuals select themselves into a group, causing a biased sample with non-probability sampling.
  • There may be a purposeful intent on the part of respondents leading to self-selection bias whereas other types of selection bias may arise more inadvertently, possibly as the result of mistakes by those designing any given study.

• Samples

  • A sample is a set of data collected and/or selected from a population by a defined procedure.
  • In statistics and quantitative research methodology, a data sample is a set of data collected and/or selected from a population by a defined procedure.
  • The best way to avoid a biased or unrepresentative sample is to select a random sample, also known as a probability sample.
  • Online and phone-in polls produce biased samples because the respondents are self-selected.
  • In self-selection bias, those individuals who are highly motivated to respond-- typically individuals who have strong opinions-- are over-represented, and individuals who are indifferent or apathetic are less likely to respond.

• Chance Error and Bias

  • Chance error and bias are two different forms of error associated with sampling.
  • In statistics, sampling bias is a bias in which a sample is collected in such a way that some members of the intended population are less likely to be included than others.
  • Selection from a specific real area.
  • Self-selection bias, which is possible whenever the group of people being studied has any form of control over whether to participate.
  • Exclusion bias, or exclusion of particular groups from the sample.

• Biases in Experimental Design: Validity, Reliability, and Other Issues

  • This may be the result of purposeful selection of participants by the researcher, but there are many other factors that can create sampling bias.
  • Selection bias happens when the comparisons in data from the sample population have no meaning or value because the participants in the sample were not equally and fairly selected for both the experimental and control groups.
  • Response bias (also known as "self-selection bias") occurs when only certain types of people respond to a survey or study.
  • This is because only a select few have answered the survey and participated in the experiment.
  • In both of these examples, people who "self-select" themselves for the study are likely to differ in important ways from the population the experimenter wishes to draw conclusions about.

• Expect Selective Exposure

  • Media forms such as the internet, television, and paper sources are also inclined to selective bias.
  • Selective exposure has been demonstrated in various contexts such as self-serving situations and situations where people hold prejudices regarding out-groups, particular opinions, and personal and group-related issues.
  • Changing beliefs about one's self, other people, and the world are all challenges that cause people to fear new information.
  • This article suggests that confirmation bias is prevalent in decision making.
  • Throughout the four experiments, generalization was reliably considered valid and confirmation bias was always present when test subjects sought new information and made decisions.

• Cognitive Biases

  • Perceptual distortions, such as cognitive bias, can result in poor judgement and irrational courses of action.
  • Bias arises from various processes that can be difficult to distinguish.
  • Self-serving bias - Another common bias is the tendency to take credit for success while passing the buck on failure.
  • Belief bias - Individuals often make a decision before they have all the facts.
  • Framing - It is quite easy to be right about everything if you carefully select the context and perspective on a given issue.

• Media Bias

  • Media bias is the bias of journalists and news producers in the selection of events and stories that are reported, and how they are covered.
  • Media bias is the bias of journalists and news producers within the mass media, concerning the selection of events and stories that are reported, and how they are covered.
  • Because it is impossible to report everything, selectivity is inevitable.
  • The most commonly discussed forms of bias occur when the media support or attack a particular political party, candidate, or ideology; however, other common forms of bias exist, including advertising bias, corporate bias, mainstream bias, sensationalism, and concision bias.
  • Advertising bias refers to when stories are selected or slanted to please advertisers; corporate bias refers to when stories are selected or slanted to please corporate owners of media; mainstream bias refers to a tendency to report what everyone else is reporting, and to avoid stories that will offend anyone.

• Using Chance in Survey Work

  • We then interview the selected person and find their income.
  • (The person who is selected from that household can be loosely viewed as also representing the person who isn't selected. )
  • Such designs are also referred to as 'self-weighting' because all sampled units are given the same weight.
  • It involves the selection of elements based on assumptions regarding the population of interest, which forms the criteria for selection.
  • These conditions give rise to exclusion bias, placing limits on how much information a sample can provide about the population.

• Personal Biases

  • Confirmation bias: This is probably the most common and the most subliminal, as many people naturally exhibit this bias without even knowing it.
  • Often times called selective search for evidence, confirmation bias occurs when decision makers seek out evidence that confirms their previously held beliefs, while discounting or diminishing the impact of evidence in support of differing conclusions.
  • Overconfidence bias: This is another potentially disruptive personal bias and occurs when a person subjectively overestimates the reliability of their judgments versus an objectively accurate outcome.
  • Groupthink: This is a bias within group decision making that leads the group toward harmony rather than a realistic evaluation of alternatives.
  • Other personal biases can take on a variety of forms and may extend to either the holder of the bias or to external parties.