Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Bias

Bias

Bias refers to any tendency that prevents a question from being considered unprejudiced. In research, bias occurs when one outcome or answer is selected or encouraged over others in sampling or testing. Bias can occur during any research phase, including study design, data collection, analysis, and publication.
In statistics, a sampling bias is created when a sample is collected from a population, and some members of the population are not as likely to be chosen as others (remember, each member...

Bias in Epidemiological Studies

Bias in Epidemiological Studies

Biases can arise at various stages of research, from study design and data collection to analysis and interpretation. Recognizing and addressing these biases is essential to ensure the validity and reliability of epidemiological findings.Broadly speaking, biases in epidemiology fall into three main categories: selection bias, information bias, and confounding. A more detailed description of possible biases is:

Blind Procedures

Blind Procedures

Ideally, the people who observe and record the children’s behavior are unaware of who was assigned to the experimental or control group, in order to control for experimenter bias. Experimenter bias refers to the possibility that a researcher’s expectations might skew the results of the study. Remember, conducting an experiment requires a lot of planning, and the people involved in the research project have a vested interest in supporting their hypotheses. If the observers knew which child was...

Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches

Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches

Biopharmaceutical studies constitute a vital field aiming to enhance drug delivery methods and refine therapeutic approaches, drawing upon diverse interdisciplinary knowledge. In research methodologies, the choice between controlled and non-controlled studies significantly influences the study's reliability and accuracy.
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast, controlled...

Blinding

Blinding

Blinding is a commonly used method of not telling participants which treatment a subject is receiving. Blinding is a critical part of a randomized control trial or RCT. It reduces the bias that affects the results. In an RCT, blinding is used in the form of a placebo. A placebo effect occurs when untreated subjects falsely believe they have received the treatment and report improved symptoms. A placebo or a dummy treatment is administered to subjects to negate the bias caused by such an effect.

Confirmation Biases

Confirmation Biases

The confirmation bias is the tendency to focus on information that confirms our existing beliefs and ignore information that is inconsistent with our expectations. For example, if you think that your professor is not very nice, you notice all of the instances of rude behavior exhibited by the professor while ignoring the countless pleasant interactions he is involved in on a daily basis. Have you ever fallen prey to the confirmation bias, either as the source or target of such bias?

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Coronal deformity of the knee in childrens and adolescents. A systematic review of current orthopaedics treatments.

La Clinica terapeutica·2024

Same author

High-Grade Chondrosarcoma of the Proximal Phalanx: an Unusual Case of a Rare Entity.

Acta chirurgiae orthopaedicae et traumatologiae Cechoslovaca·2023

Same author

Reconstruction of metatarsal bone after giant cell tumor resection with no vascularized fibular graft in a pediatric patient: Case report and review of literature.

Frontiers in pediatrics·2022

Same author

Rare lysosomal disease registries: lessons learned over three decades of real-world evidence.

Orphanet journal of rare diseases·2022

Same author

Wide resection for giant-cell tumor of the distal radius: which reconstruction? A systematic review of the literature and pooled analysis of 176 cases.

Hand surgery & rehabilitation·2022

Same author

Massive bone allograft engineered with autologous vessels: A new perspective for the future.

Hand surgery & rehabilitation·2022

Search research articles

Related Experiment Video

Updated: Jul 10, 2026

Inverse Probability of Treatment Weighting (Propensity Score) using the Military Health System Data Repository and National Death Index

Inverse Probability of Treatment Weighting (Propensity Score) using the Military Health System Data Repository and National Death Index

Published on: January 8, 2020

Bias in clinical research.

G Tripepi¹, K J Jager, F W Dekker

¹CNR-IBIM, Clinical Epidemiology and Physiopathology of Renal Diseases and Hypertension, Reggio Calabria, Italy. gtripepi@ibim.cnr.it

Kidney International

|November 6, 2007

Summary

This study explains how systematic errors, known as bias, can compromise clinical research quality. It details selection bias and information bias types, crucial for ensuring study validity.

Related Experiment Videos

Last Updated: Jul 10, 2026

Inverse Probability of Treatment Weighting (Propensity Score) using the Military Health System Data Repository and National Death Index

Inverse Probability of Treatment Weighting (Propensity Score) using the Military Health System Data Repository and National Death Index

Published on: January 8, 2020

Area of Science:

Clinical research methodology
Epidemiology
Biostatistics

Background:

Clinical study quality hinges on internal and external validity.
Internal validity means observed differences are solely due to the exposure studied, excluding random error.
Systematic errors, termed bias, can compromise internal validity during study design or execution.

Purpose of the Study:

To define and categorize major biases affecting clinical study internal validity.
To elucidate the concepts of selection bias and information bias.
To provide a comprehensive overview of specific bias types within these categories.

Main Methods:

Focus on two primary bias categories: selection bias and information bias.
Describe specific types of selection bias: incidence-prevalence bias, loss-to-follow-up bias, and publication bias.
Detail various information biases: misclassification bias (including recall, interviewer, observer, and regression dilution bias) and lead-time bias.

Main Results:

Selection bias arises from systematic differences in study group selection.
Information bias stems from systematic errors in measurement or classification of exposure or outcome.
Specific biases like recall bias, interviewer bias, and publication bias were detailed.

Conclusions:

Understanding and mitigating selection and information bias is essential for robust clinical research.
Awareness of these bias types aids researchers in designing and interpreting studies accurately.
Proper identification of bias types improves the overall reliability and validity of clinical evidence.