observer bias

Examples of observer bias in the following topics:

• Observation

  • Participant observation involves the researcher joining a sample of individuals without interfering with that group's normal activities in order to document their routine behavior or observe them in a natural context.
  • Often researchers in observational studies will try to blend in seamlessly with the sample group to avoid compromising the results of their observations.
  • These observations also capture behavior that is more natural than behavior occurring in the artificial setting of a lab and that is relatively free of some of the bias seen in survey responses.
  • There are also ethical concerns related to observing individuals without their consent.
  • Without the use of multiple researchers, the chances of observer bias increase; because behavior is perceived so subjectively, it is possible that two observers will notice different things or draw different conclusions from the same behavior.

• Cultural Influences on Perception

  • Attribution theory, also called actor-observer bias, focuses on the attribution or causes of an action.
  • The Egocentric bias causes individuals to think more positively about themselves than others think of them.
  • The Over-confidence bias causes individuals to overestimate their own confidence.
  • The Status Quo bias demonstrates that individuals give preference to things which are familiar.
  • The Ingroup bias shows a preference for individuals who are in one's own group affiliation.

• Sampling Bias

  • This section discusses various types of sampling biases including self-selection bias and survivorship bias.
  • A common type of sampling bias is to sample too few observations from a segment of the population.
  • Survivorship bias occurs when the observations recorded at the end of the investigation are a non-random set of those present at the beginning of the investigation.
  • Gains in stock funds is an area in which survivorship bias often plays a role.
  • Therefore, there is a bias toward selecting better-performing funds.

• Cognitive Biases

  • Perceptual distortions, such as cognitive bias, can result in poor judgement and irrational courses of action.
  • Essentially, there must be an objective observer to identify cognitive bias in a subjective individual.
  • 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.

• Creating a test statistic for one-way tables

  • While some sampling variation is expected, we would expect the sample proportions to be fairly similar to the population proportions if there is no bias on juries.
  • H 0 : The jurors are a random sample, i.e. there is no racial bias in who serves on a jury, and the observed counts reflect natural sampling fluctuation.
  • H A : The jurors are not randomly sampled, i.e. there is racial bias in juror selection.
  • To evaluate these hypotheses, we quantify how different the observed counts are from the expected counts.

• Distorting the Truth with Descriptive Statistics

  • The following are examples of statistical bias.
  • Detection bias occurs when a phenomenon is more likely to be observed and/or reported for a particular set of study subjects.
  • Reporting bias involves a skew in the availability of data, such that observations of a certain kind may be more likely to be reported and consequently used in research.
  • Analytical bias arises due to the way that the results are evaluated.
  • identify the cause behind the phenomenon because it only describes and reports observations;

• Confounding

  • Confounding by indication has been described as the most important limitation of observational studies.
  • Confounding by indication occurs when prognostic factors cause bias, such as biased estimates of treatment effects in medical trials.
  • Double blinding conceals the experiment group membership of the participants from the trial population and the observers.
  • By preventing the observers from knowing of their membership, there should be no bias from researchers treating the groups differently or from interpreting the outcomes differently.
  • Break down why confounding variables may lead to bias and spurious relationships and what can be done to avoid these phenomenons.

• Heuristics and Cognitive Biases

  • When interpreting data, a researcher must avoid cognitive bias and be aware of the use of heuristics to avoid drawing incorrect conclusions.
  • However, this heuristic can introduce bias in research, in which it is by definition important to remain an objective observer.
  • A cognitive bias is the mind's tendency to come to incorrect conclusions based on a variety of factors.
  • Hindsight bias occurs in psychological research when researchers form "post hoc hypotheses."
  • Confirmation bias is especially dangerous in psychological research.

• Chance Error and Bias

  • Chance error and bias are two different forms of error associated with sampling.
  • In statistics, a sampling error is the error caused by observing a sample instead of the whole population.
  • If the observations are collected from a random sample, statistical theory provides probabilistic estimates of the likely size of the error for a particular statistic or estimator.
  • 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.
  • Exclusion bias, or exclusion of particular groups from the sample.

• Historical Bias