Comparing Lab Results from Different Labs

Cereal Killer wrote:

PUBLIC ANNOUNCEMENT: "Anyone wanting to look smart should not try to do so in a public forum, since smart people never post in public forums."

There. That should cover it.

Except you have confused "smart" with "wise".

Thanks. I'll reword, then.

NEW PUBLIC ANNOUNCEMENT: "Anyone wanting to look like a smart-aleck wiseguy should please do so only in public forums, since only smart-aleck wiseguys post in public forums."

Thanks, again, Ms. Killer.



ps-Actually, good point, CK, --AND it made me laugh. Which is more important to me most days.

JDS74, I appreciate the information that you posted and understand the point that you were attempting to make.

In my business we regularly get water analyses from different laboratories. We sometimes create duplicate samples with different labels and send them for analysis or send the same sample to different labs. It is amazing how frequently the results do not correlate well. A good lab tech can get very reproducible results, but these individuals rarely last on the "simple" test procedures. So the reproducibility and the reliability suffers. Compound this with different procedures from different labs based upon different calibration systems and black and white starts to become VERY gray.

jnk wrote:
Thanks. I'll reword, then.

NEW PUBLIC ANNOUNCEMENT: "Anyone wanting to look like a smart-aleck wiseguy should please do so only in public forums, since only smart-aleck wiseguys post in public forums."

Thanks, again, Ms. Killer.



ps-Actually, good point, CK, --AND it made me laugh. Which is more important to me most days.

I was serious and my comment was not directed toward you - only toward the words used. "Smart" and "wise" are two different animals.

Not saying I am not often a smartass, just that my comment here was serious.

"Smart" and "wise" are two different animals.

Yep.

I think Elwood P. Dowd put it best:

"Years ago my mother used to say to me, she'd say, 'In this world, Elwood, you must be' -- she always called me Elwood -- 'In this world, Elwood, you must be oh so smart or oh so pleasant.' Well, for years I was smart. I recommend pleasant. You may quote me."

From the first time I saw that movie (Harvey), I've always enjoyed quoting Elwood quoting his mother.

So I'll change my announcement one last time: "It ain't wise to try to be too smart on a forum, and it ain't so smart to try to be too wise there neither."

I'll just work at trying to be nicer. Like Elwood. Even though no one has ever accused me of being either smart or wise, other than my occasional smart-aleck wisecracks.

jnk wrote:Even seasoned pitchers from the big leagues pitch underhanded when playing in the public park.

I really love that! I'm so glad I understand baseball!

DoriC wrote:

jnk wrote:Even seasoned pitchers from the big leagues pitch underhanded when playing in the public park.

I really love that! I'm so glad I understand baseball!

I don't think big-league baseball is allowed in NJ, is it?

My roots are in The Bronx!! What's the name of that team that plays there??

jnk wrote:

"Smart" and "wise" are two different animals.

Yep.

I think Elwood P. Dowd put it best:

"Years ago my mother used to say to me, she'd say, 'In this world, Elwood, you must be' -- she always called me Elwood -- 'In this world, Elwood, you must be oh so smart or oh so pleasant.' Well, for years I was smart. I recommend pleasant. You may quote me."

From the first time I saw that movie (Harvey), I've always enjoyed quoting Elwood quoting his mother.

So I'll change my announcement one last time: "It ain't wise to try to be too smart on a forum, and it ain't so smart to try to be too wise there neither."

I'll just work at trying to be nicer. Like Elwood. Even though no one has ever accused me of being either smart or wise, other than my occasional smart-aleck wisecracks.

"IMHO", hearts and flowers, Celine Dion music playing in background, I'm dumber than a bag of rocks, scum of the earth, should be living in a Planter's can...

You have a near-obsession to appear Tom Sawyer-clever rather than either smart or wise.

JDS74 wrote:Since molette (aka sludge) took offense at my original post, here is a link to a scholarly paper discussing the underlying science related to this topic.

...
And another reference

...

Thanks very much for those links! I'm sure they will prove quite helpful to everyone on the forum!

One thing though-- I don't see any references to using Z-scores to compare interlab results. Could you expound on that a little please?

Thanks again for your comments!

? wrote:Tom Sawyer-clever rather than either smart or wise.

Not sure if that's a Mark Twain reference or a Neil Peart reference.

Either way, I'll take it.

Thanks, Uncle Dave!

DoriC wrote:My roots are in The Bronx!! What's the name of that team that plays there??

Red Sox?

jnk wrote:

? wrote:Tom Sawyer-clever rather than either smart or wise.

Not sure if that's a Mark Twain reference or a Neil Peart reference.

Neil.

Now there's a guy with rotten luck.

jnk wrote:Thanks, Uncle Dave!

Actually, that one wasn't me.

Sludge wrote:Actually, that one wasn't me.

Sorry.

I guess I got fooled again.

Probably Banned.

More proof of the futility of attempts to appear smart or wise in an Internet forum!

As for the deeper question at hand, I don't claim to understand the science or the math, but it may be that views of the idea of the use of z/zeta for interlab comparison differ according to industry, continent, and purpose. Like most things, what is done in day-to-day practice may differ from what is done in scientific studies designed to point out the limitations of supposedly standardized testing processes and procedures for measuring that which involves certain levels of mathematical uncertainty.

http://web.vscht.cz/~kocourev/en_GB/fil ... 202012.pdf
http://irmm.jrc.ec.europa.eu/EURLs/EURL ... 4314en.pdf

Then again, I may just not understand the questions or arguments being posed.

jnk wrote:Links

Proficiency testing!

Now why didn't I think of that!