If the packets hold no figures, the research must. Reports on roasting do carry names for levels: light, medium and dark roasting; weak, medium and strong. Put the shops' words and the research levels into one table and it starts to look as though a dark roast could be settled at roughly so many degrees.
Can a table be built that matches the shops' light and dark roasts to the levels used in research?
Across shops, no. What can be built is the relative order inside one shop. On the research side too, the levels are made differently from one document to the next. What matches across them is the names of the levels, and nothing else.
Temperatures cannot be set side by side across documents
Kochi measured the exhaust air, NARO the surface of the leaf, and Ishikawa the inner wall of the drum.