- ascertainment bias
- systematic error causing failure to represent equally all groups of cases or persons that should be represented in a sample.
Medical dictionary. 2011.
ascertainment bias
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Ascertainment bias — In scientific research, ascertainment bias occurs when false results are produced by non random sampling and conclusions made about an entire group are based on a distorted or nontypical sample. If this is not accounted for, results can be… … Wikipedia
Bias — This article is about different ways the term bias is used . For other uses, see Bias (disambiguation). Bias is an inclination to present or hold a partial perspective at the expense of (possibly equally valid) alternatives. Bias can come in many … Wikipedia
Bias — In a clinical trial, bias refers to effects that a conclusion that may be incorrect as, for example, when a researcher or patient knows what treatment is being given. To avoid bias, a blinded study may be done. * * * 1. Systematic discrepancy… … Medical dictionary
Sampling bias — In statistics, sampling bias is when a sample is collected in such a way that some members of the intended population are less likely to be included than others. It results in a biased sample, a non random sample[1] of a population (or non human… … Wikipedia
Experimenter's bias — In experimental science, experimenter s bias is subjective bias towards a result expected by the human experimenter. David Sackett,[1] in a useful review of biases in clinical studies, states that biases can occur in any one of seven stages of… … Wikipedia
Confirmation bias — (also called confirmatory bias or myside bias) is a tendency for people to favor information that confirms their preconceptions or hypotheses regardless of whether the information is true.[Note 1][1] As a result, people gather evidence and recall … Wikipedia
Selection bias — is a statistical bias in which there is an error in choosing the individuals or groups to take part in a scientific study.[1] It is sometimes referred to as the selection effect. The term selection bias most often refers to the distortion of a… … Wikipedia
Cognitive bias — For an article about the conceptual problems of the mind see Cognitive closure (philosophy). Psychology … Wikipedia
Omitted-variable bias — In statistics, omitted variable bias (OVB) occurs when a model is created which incorrectly leaves out one or more important causal factors. The bias is created when the model compensates for the missing factor by over or under estimating one of… … Wikipedia
Outcome bias — The outcome bias is an error made in evaluating the quality of a decision when the outcome of that decision is already known. Overview One will often judge a past decision by its ultimate outcome instead of based on the quality of the decision at … Wikipedia
