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...

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,...

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

Adjudicating Heart Failure Events in Participants Receiving Hemodialysis: Findings from Evaluation of Cinacalcet Hydrochloride Therapy to Lower Cardiovascular Events (EVOLVE) Trial.

American journal of nephrology·2026

Same author

Examining the Direct and Indirect Effects of Socioeconomic Status on Colorectal Cancer Using Structural Equation Modeling.

Cancer investigation·2025

Same author

Safety Endpoints With Vadadustat Versus Darbepoetin Alfa in Patients With Non<b>-</b>Dialysis-Dependent CKD: A Post Hoc Regional Analysis of the PRO<sub>2</sub>TECT Randomized Clinical Trial of ESA-Treated Patients.

Kidney medicine·2023

Same author

Safety Endpoints With Vadadustat Versus Darbepoetin Alfa in Patients With Non-Dialysis-Dependent CKD: A Post Hoc Regional Analysis of the PRO<sub>2</sub>TECT Randomized Clinical Trial of ESA-Naïve Patients.

Kidney medicine·2023

Same author

Associations between polymorphisms in leptin and leptin receptor genes and colorectal cancer survival.

Cancer biology & medicine·2023

Same author

Vadadustat for treatment of anemia in patients with dialysis-dependent chronic kidney disease receiving peritoneal dialysis.

Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association·2023

Search research articles

Related Experiment Video

Updated: Nov 8, 2025

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.

Susan Stuckless¹, Patrick S Parfrey²

¹Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL, Canada. c45sns@mun.ca.

Methods in Molecular Biology (Clifton, N.J.)

|April 19, 2021

Summary

This summary is machine-generated.

Understanding epidemiological bias is crucial for accurate clinical research. This review details selection, information, and intervention biases, plus confounding, to improve study validity.

Keywords:

Confounding Epidemiology Information bias Intervention bias Selection bias Validity

More Related Videos

A Novel Method for Involving Women of Color at High Risk for Preterm Birth in Research Priority Setting

A Novel Method for Involving Women of Color at High Risk for Preterm Birth in Research Priority Setting

Published on: January 12, 2018

Author Spotlight: Increasing TMS Accessibility Through Braiding Techniques for Diverse Hair Types

Author Spotlight: Increasing TMS Accessibility Through Braiding Techniques for Diverse Hair Types

Published on: August 9, 2024

Related Experiment Videos

Last Updated: Nov 8, 2025

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

A Novel Method for Involving Women of Color at High Risk for Preterm Birth in Research Priority Setting

A Novel Method for Involving Women of Color at High Risk for Preterm Birth in Research Priority Setting

Published on: January 12, 2018

Author Spotlight: Increasing TMS Accessibility Through Braiding Techniques for Diverse Hair Types

Author Spotlight: Increasing TMS Accessibility Through Braiding Techniques for Diverse Hair Types

Published on: August 9, 2024

Area of Science:

Epidemiology
Clinical Research

Background:

Clinical epidemiology assesses disease burden, diagnosis, prognosis, and treatment efficacy.
A key focus is establishing exposure-outcome relationships to determine prevalence, incidence, cause, prognosis, or treatment effects.

Purpose of the Study:

To review fundamental epidemiological concepts.
To discuss potential biases and confounders impacting study validity.
To outline methods for minimizing bias in clinical research.

Main Methods:

Review of epidemiological concepts.
Discussion of bias types: selection, information, intervention, and confounding.
Analysis of bias impact on observed effects.

Main Results:

Study validity hinges on addressing biases and confounders.
Bias can distort the magnitude and direction of observed effects.
Understanding bias types is essential for accurate conclusions.

Conclusions:

Minimizing bias is critical for reliable epidemiological findings.
Awareness and assessment of bias enhance the validity of clinical research.
This review provides a foundation for mitigating bias in epidemiological studies.