I am new to the group. Have a question i could not find a direct answer through a site search.
Im comparing a standard MSA reference with a new publication by Donald Wheeler which essentially states that most everything published prior to today on Gage R&R is wrong and misleading.
In Wheelers article he references two methods of obtaining an estimation of the standard deviation, using the control chart method:
R/d2 and R/d2*
He doesnt site how d2* is calculated or where one could go to get a table of values for it. Im not an expert in statistics and could not find this anywhere on the net.
Any ideas? e.g, im using a subgroup size of 3, for which d2=1.693, however in his paper, his d2* = 1.906.
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