Data should be looked upon as knowledge, not as a reflection of the real world

The leading view on data is that data are a reflection of the real world. Data are almost like a mirror. Data are often considered an abstraction of the real world. When the data are correct the real world can be known. 

Considering data as a reflection of reality does not take into account that data have a context. The following aspects of context influence the data:
  • the intentions of the supplier of the data: what does the supplier want to reach by providing this information? (see also "Data cannot be separated from the objectives for which the data are created")
  • the general knowledge of the supplier
  • the exposure to the real world: what did the supplier see?
  • the interpretation of the real world: what does the supplier think he saw?
  • the choice of words (or other codes). This depends on what the supplier thinks what these words or codes mean.
Suppose that the supplier of the data is honest. Even than the data are highly subjective. Data reflect the understanding of the real world, not the real world as such.