For example, say I want to determine the atomic structure of a bio molecule. I purify the molecule, get it to crystallize (probably though trial and error), shoot it with X-rays, observe the scatter amplitudes, determine the scatter phases through an optimization procedure involving prior data, determine atomic coordinates, and possibly do additional refinement until I have the final structure. Is this a [*measurement*](http://en.wikipedia.org/wiki/Measurement) of the structure or an [*experiment*](http://en.wikipedia.org/wiki/Experiment) to determine it? Or something else?

Maybe it's an issue of linguistics, I'm not sure. Perhaps a measurement just gives a number, but an experiment answers a *question* based on a measurement? If x-ray crystallography is an experiment, what is the question it's answering?