What commonalities do we have?

Efficiencies and background subtractions

  • Store the background subtraction and scaling in the output
  • Background subtraction is a reduction step and should be stored in a reproducible fashion
  • It is equally as important to store what has not been done to the data
  • Don’t try and deconvolve resolution

Detector corrections

  • Store corrections!
  • Masking, noise and monitors


  • No defined q points should be expected
  • The bin width should be inclded in the resolution
  • Log binning might be a nice general agreement
  • Neutron event mode helps with summing (although ill defined)

Instrumental information

  • Everything in metadata!!
  • Everything should be defined as a value or an array
  • The slit positions (and motor uncertainties) should be stored

Documentation: undocumented methods are useless

  • a resource to store this in an agreed way
  • link to publications (DOI)
  • include docs in files
  • a web resource could help users fix problems themselves (possibly including YouTube videos)
  • in particular if reduction method and software is available, however specific metadata needs to be stored

Do the corrections if you can

  • with error propagation
  • Would a data reduction round robin be interesting?
  • correct for “strange” experimental results if you can

Live data reduction is important for a “quick look”

What is reduction and what is analysis?

  • These are reduction:
    • footprint
    • overillumination
    • polarisation