Ligo has detected gravitational waves 100 years after Einstein predicted their existence. In other words, Einstein build up the theory of gravity without having proved the existence of gravitational waves. This fact has reminded me one of his most famous quotations: “Imagination is more important than knowledge”.
Imagination understood not as the action of making up new ideas with no empirical base but just the flexible articulation of thoughts derived from the first but not definite results of one research. In the same way, the results derive from case study based research or qualitative approach often do not allow to extrapolate the results to the whole universe under study (usually for lacking representativeness). Yet, the data obtained may give rise to new theories or hypothesis to be tested later under a positivist approach and be (or not) scientifically validated. This is not a banal issue, since qualitative data is usually excluded (usually by natural scientist and/or scientism) as part of scientific knowledge for not having been obtained by the application of the experimental method. But they are an essential part of the research process.
What is your source for the Einstein quotation?
This is the source http://www.quotationspage.com/quote/3098.html Note that I am aware that there are some fake Einstein quotation but, first, I couldnt find any evidence that this is fake and, second, regardless the quotation is attibuted to Einstein or not, I do agree with it.