Sorry, Lubo,
my sentences refer primarily to the things called "semi-quantitative"
analysis as published commonly in geosciences. Maybe this holds also for
some other results what have been claimed to be "quantitative", but I
don't want to generalize this statement to all QPA work. I'm sure that
some published results do fulfill the demands for a serious analytical work.
Greetings
Reinhard
Am 14/11/2014 08:25, schrieb Lubomir Smrcok:
This is the best description of quantitative phase analysis by X-rays
I have ever read ...
Very true is especially this part :
"... is attributed to data where an estimationof errors is missing,
that have been never cross-checked by an
independent method, and so they are suspected to be biased by serious
systematic errors. If so, than datasets originating from different
sources cannot be treated seriously together in a statistical
evaluation, per definition."
Thanks a lot !
lubo
On Fri, 14 Nov 2014, Reinhard Kleeberg wrote:
I don't think that the term "semi-quantitative" is defined sharp
enough to provide a basis for a serious statistical evaluation. In
geosciences typically "semi-quantitative" is attributed to data where
an estimation of errors is missing, that have been never
cross-checked by an independent method, and so they are suspected to
be biased by serious systematic errors. If so, than datasets
originating from different sources cannot be treated seriously
together in a statistical evaluation, per definition. In the best
case, they can be used to compare samples of one series measured with
the same instrument and analyzed by the same procedure. Unfortunately
many authors report "wt%" even in "semi-quantitative" phase analysis,
what suggests compatibility. This is misleading and should be
avoided. For the statistical evaluation of a series of comparably
measured diffraction patterns of one geological object it seems more
serious to apply cluster analysis of the raw patterns or to use any
intensity ratios. But of course the best way is to improve the
evaluation method to be really "quantitative", i.e. free of
systematic error and evaluated by realistic e.s.d.'s.
Reinhard Kleeberg
Am 13/11/2014 18:53, schrieb James Talbot:
Hello All,
I had the following request from a client:
"I am looking for examples of statistics used on semi-quantitative
data, i.e. comparing XRD results of multiple samples. Do you have
any recommendations or know of any papers that clearly explain their
statistical methods? In so many papers, it is glossed over. I have
a pretty good handle on my stats, but would prefer to see what other
have done with XRD datasets."
Can anyone help with this.? I do not know of any of the top of my
head.
Thanks in advance,
James Talbot
K-T GeoServices, Inc.
970-641-1235 (office)
940-597-9076 (mobile)
219 North Iowa Street, Unit J
Gunnison CO 81230-2479
www.ktgeo.com
--
TU Bergakademie Freiberg
Dr. R. Kleeberg
Mineralogisches Labor
Brennhausgasse 14
D-09596 Freiberg
Tel. ++49 (0) 3731-39-3244
Fax. ++49 (0) 3731-39-3129
--
TU Bergakademie Freiberg
Dr. R. Kleeberg
Mineralogisches Labor
Brennhausgasse 14
D-09596 Freiberg
Tel. ++49 (0) 3731-39-3244
Fax. ++49 (0) 3731-39-3129
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