Bias in research results

Research bias, also called experimenter bias, is a process where the investigator performing the research influences the results, in order to portray a certain outcome. This can have a huge effect on the credibility of the results because without fully explaining how the results limited or eliminated bias the results cannot possibly be trusted. 

Some bias in research arises from experimental error and failures to take into account all of the possible variables. Other research bias arises when researchers select subjects that are more likely to generate the desired results, a reversal of the normal processes governing science.

Research bias is the one factor that makes qualitative research much more dependent upon experience and judgment than quantitative research. (Quantitative Research denial of any Research Bias, Qualitative Research Bias Acceptance and Acknowledgment of Research Bias)

The main point to remember with research bias is that, in many disciplines, it is unavoidable. Any experimental design process involves understanding the inherent biases and minimizing the effects. In quantitative research, the researcher tries to eliminate bias completely whereas, in qualitative research, it is all about understanding that it will happen.

One thing that can influence bias is if the project is funded. The source of funding for a research project may bias the reporting of results. The funding source is usually included in the results. When reading an article from a funded research project, you must consider whether the funders of this research had anything to gain by the results. When research is paid for by a source that does not have an interest in the results, funder's expectations or preferences were less likely to have influenced the results.

References:

http://www.experiment-resources.com/research-bias.html

http://www.cdc.gov/des/consumers/research/understanding_deciding.html