“Facts are needed to establish theories but theories are needed to make sense of facts.” 

Fact: Something that has been repeatedly confirmed and can be re-tested and can give the same results. 
Theory: Something that can be explained very well, however has very vague truths. 

Areas Of Knowledge

Natural Sciences- e.g. Biology, Chemistry and Physics- these sciences most involve getting information and results from an experiment to create facts, rather than a theory, however there have been theories in the past that have had experiments conducted on them to establish facts. Moreover, the experiments conducted in this area of knowledge are more likely more reliable and less subjective, more objective. At times, there can be uncertainties which can have an effect on the overall results.

Human Sciences- e.g. Psychology... - in subjects such as Psychology, experiments are conducted, however they are mostly based on concluding results based on human behaviour rather than 'facts of life'. 

History- History is an area where things happened in the past; most people have not lived through the events, therefore can not explain them very well and moreover views can change and bias is more likely to occur.