If you said "yes" or "it depends", what funding sources do you trust most? (scale of 1-5, 1 being lowest, 5 being highest).

It's all about study design and publication of the methods

No single source of funding is completely devoid of certain biases. However, usually governments and NGOs are more reliable than industry sources.

Known cases

All NGO's have a mission.

For any group attempting to achieve a specific goal, there is a strategic advantage to intentionally selecting or limiting scientific parameters in a way that seems to answer a question favorably, but only provide part of the story. As a scientific community, we have a responsibility to illuminate the whole truth with appropriate studies and parameters, as present technology allows. Funding is a limitation to this. It is exceptionally high-pressure and politically challenging to publish study results that challenge an existing narrative for NGOs with a known regulatory bias/mission, as the entire Client base is an outraged public. Lower regulation, high revenue fields have similar exceptional pressures in the form of monetary stakeholders. Highly regulated fields, like pharmaceuticals, have extensive government oversight, which prevails. There are cultural variations from company to company and NGO to NGO that diverge from these identified trends.

The more vested a funding source, the less likely it will be independent. Researchers might be apprehensive that they cannot be fully objective shall they want to be successful in getting the current grant or future grants.

In my opinion Government and the NGO with no known regulatory bias are most trusted and certainly would not interfere in the collection, analysis and interpretation of data in a certain way.

risks of conflict and bias greater with direct funding. Lower with "hands-off" or indirect funding. Bias may be direct and/or perceived by readers or public

Government funding body panels may be biased towards particular institutes or people, but usually not towards a particular research study.

It's of general opinion and not necessarily all those studies within that can be rated highly confidence or the opposite. Depends on individual studies.

Industry has to perform toxicity studies under strict QA, other claims regarding product properties also have to be verifiable. Only some claims regarding food benefits are questionable. I have had several interferences regarding research results by government agencies. In my experience, NGO supported research often is of low quality and exaggerates relevance of their results

Only non interested partners or, highly regulated, externally refereed funding sources are completely reliable.

A good reviewer checks the findings against the funder. Sometimes a chemical, food or pharmaceutical product needs to be tested and the only way it can be done is if they pay for it. For instance, animal feed needs to be tested by law. So the research is done and it is submitted to the State so the feed can be registered. Its OK to report this as part of a scientific paper, even although the feed company paid the lab to test the feed.

Government should be the least biased while NGOs with an axe to ground could be as bad a industry folks. Much of all of this depends on the transparency of the research as reported.

Cuando alguna organización participa con recursos para financiar una investigación, es importante considerar los intereses declarados

Chemical and Pharma sector, one must need pure molecules and for that good quality research needed