What Is Research Bias?

Research bias is one of the threats to validity in qualitative research. Research bias occurs because researchers bring into studies their own personal beliefs, values, experiences, and bias. Research bias is considered a threat due to an error being introduced into sampling or testing by selecting or encouraging one outcome or answer over others (Pannucci & Wilkins, 2010, p. 619). Researchers are prone to human error and therefore they make mistakes and get things wrong (Norris, 1997). To minimize researcher bias five types of research biases have been identified. According to Smith and Noble (2014) the types of research biases are the following: design bias, selection/participation bias, data collection and measurement bias, analysis bias, and publication bias.
1. Design bias is poor design and incongruence
Publication bias occurs when Published studies nearly always have some degree of bias. For example, in quantitative research, studies are more likely to be published if reporting statistically significant findings. Non-publication in qualitative studies is more likely to occur because of a lack of depth when describing study methodologies and findings are not clearly presented (p. 101).
Different forms of research may be prone to different sources of error, but clearly none immune (Norris, 1997 p. 173). Research bias allows readers to critically and independently review the scientific literature and avoid treatments which are suboptimal or potentially harmful (Pannuci & Wilkins, 2010).

References
Nigel Norris (1997) Error, bias and validity in qualitative research, Educational Action Research, 5(1), 172-176. http://dx.doi.org/10.1080/09650799700200020
Pannucci, C. J., & Wilkins, E. G. (2010). Identifying and Avoiding Bias in Research. Plastic and Reconstructive Surgery, 126(2), 619–625. http://doi.org/10.1097/PRS.0b013e3181de24bc
Smith, J., & Noble, H. (2014). Bias in research. Evidence Based Nursing, 17(4), 100-101.