Nato doc on The Nature of Data
PDF: http://ftp.rta.nato.int/public/PubFullText/RTO/TR/RTO-TR-HFM-073/TR-HFM-073-ANN-I.pdf
1 INTRODUCTION
The term “data” is used here in the broadest possible sense. Data are mere basic observations, which are real, not assumed or hypothesized. Data should neither be underrated nor overrated in their importance. They should certainly never be confused with the concept of absolute truth. Data can be thought of as the foundation of an epistemological system that includes information, knowledge, truth, and wisdom. This Annex discusses some of the common classifications of types of data and their treatment; for a more thorough treatment the reader should consult textbooks and other scholarly works on epistemology and statistics.