Question 22: What is in your opinion most important in a measurement? Annette Paul, PTB Working Group "Environmental radioactivity": Receptiveness to surprises Reinhard Scherm, former PTB Department "Fundamentals of Physics and Metrology": Never start an experiment Friday afternoon. And then: open-mindedness, suspiciousness, questioning of trivial self-evident truths.
Uwe Keyser, former PTB Department "Focal Points of Experimental Research": The result	Scene from the film "Das Reich und die Herrlichkeit"

Ernst O. Göbel, President of the PTB: To state the uncertainty of the measurement result as well

Gesine Grosche, PTB Working Group "Unit of Length": The model assumption and the readiness to accept deviating observations

Andreas Bauch, PTB Working Group "Unit of time": You must have good knowledge of the measurand (not of the result) and make sure that the boundary conditions allow the desired measurement to be carried out. To establish, characterize and document these boundary conditions often is more difficult than to find the appropriate measuring instrument.

Niels Bohr (1885 - 1962): 22. What is in your opinion most important in a measurement? “What is decisive is the impossibility of strictly separating the behaviour of atomic objects from the interaction with the measuring instruments serving to determine the conditions under which the phenomena occur.“

Werner Heisenberg (1901 - 1976): With good reason, the old formula “Credo ut intellegam – I believe in order to understand – has been used in Europe’s world history recently depicted by Freyer [...], and Freyer has expanded it [when applying it to the voyages of Columbus] by adding a link: “Credo ut agam; ago ut intellegam – I believe in order to act; I act in order to understand.” This formula goes not only with the first circumnavigations of the global, but also with the whole of the natural science of the Occident. It encompasses education in the humanities and natural science.”