It can be both, if it is the same control it has to go from +2 to -2sd, if it is across 2 controls, one goes up while the other goes down. From his website: “R4s indicates a rejection when one control measurement in a run exceeds a +2s control limit and another exceeds a -2s control limit. This "range" rule is sensitive to changes in the width of the distribution, therefore it is a good indicate of increases in random error or changes in the precision of the method.”
Watching this in 2023 and I’m just so grateful I’ve doing your channel. Thank you so much Dr, please continue with this amazing work!
Thank you, I will
This is one of the best lectures. Kudos to you selflessness Dr. A. Respect😊
Appreciated for your free lessons.
These lectures are amazing for continuing education for my MLT portfolio! Thank you so much!!
Most welcome!!
Good discussion.👍
i thought a r4s only applies to 2 levels of controls - is it not?
It can be both, if it is the same control it has to go from +2 to -2sd, if it is across 2 controls, one goes up while the other goes down. From his website: “R4s indicates a rejection when one control measurement in a run exceeds a +2s control limit and another exceeds a -2s control limit. This "range" rule is sensitive to changes in the width of the distribution, therefore it is a good indicate of increases in random error or changes in the precision of the method.”