The issue of bias is a very tricky one to deal with. For example, it is usually assumed in the popular media (and sometimes in the specialist media too) that if research is funded by an interest group the results cannot be free from bias. So, if you have paid me to find out something, you have no chance of me telling you the truth because I will only tell you what you want to hear. Or if I find something you do not like, you will stop me telling anyone else. This may seem like ‘common sense’ but in practice commercial or other vested interests often fund research, and in the contract to carry out the work there will be conditions relating to what can be done with the findings.
For example it is possible to have a contract that says that the findings can be published, whatever they say. Or it may be that the contract does put some restrictions on the publication of the findings, or on the design of the research, so that there are problems of bias. But unless you know the terms of the contract, you cannot know for sure.
If a mobile phone company pays for research on mobile phone safety, is that research bound to find that mobiles do not damage a user's health? Or should we be more open minded?
What do you think?