Bias is an inclination of temperament or outlook to present or hold a partial perspective, often accompanied by a refusal to consider the possible merits of alternative points of view. People may be biased toward or against an individual, a race, a religion, a social class, a political party, or a species. Biased means one-sided, lacking a neutral viewpoint, not having an open mind.

Bias can come in many forms and can also affect research. Scientists may unconsciously choose a method of study that favors their hypothesis or select a sample that is not truly representative of the population. Studies on animals or small samples may not produce results that are generalizable to humans, and studies on humans may be too short to show long-term effects.

In addition, people interpreting research findings can be biased. They may be influenced by their own beliefs, by the Way the findings are presented, or by outside factors such as who funded the research.

There are several ways to reduce bias in research. Scientists can use blind or double-blind studies, in which participants do not know which group they are in and neither do the researchers until after the data have been collected. Randomization, in which participants are assigned to groups by chance, can also help reduce bias.

It is important to remember that all research is subject to some degree of error and bias. However, by using careful methods and remaining objective, scientists can minimize the effects of bias and produce accurate results.