Statistics on semi-quantitative XRD data
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 ++ Please do NOT attach files to the whole list alan.he...@neutronoptics.com Send commands to lists...@ill.fr eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++
Antw: Statistics on semi-quantitative XRD data
James, This may be of interest: Stutzman, P. (2005). Powder diffraction analysis of hydraulic cements: ASTM Rietveld round-robin results on precision, Powder Diffraction 20(2), 97-100. The study design and statistical evaluation is based on ASTM E 691. Regards, Nicola -- Nicola Döbelin Dr. phil.-nat., Dipl. phil.-nat. Skeletal Substitutes Group RMS Foundation Bischmattstrasse 12 / P.O. Box 203 CH-2544 Bettlach / Switzerland Tel: +41 (0)32 644 19 87 / Fax +41 (0)32 644 11 76 e-mail: nicola.doebe...@rms-foundation.ch website: www.rms-foundation.ch James Talbot ja...@ktgeo.com schrieb am 13.11.2014 um 18:53: 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 ++ Please do NOT attach files to the whole list alan.he...@neutronoptics.com Send commands to lists...@ill.fr eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++
Re: Statistics on semi-quantitative XRD data
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 ++ Please do NOT attach files to the whole list alan.he...@neutronoptics.com Send commands to lists...@ill.fr eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++
Re: Statistics on semi-quantitative XRD data
Dear James, I'm not sure these are quite what you are after, but I'm suggesting them anyway. There were several papers from Gordon Barr about non-parametric methods: SNAP-1D: a computer program for qualitative and quantitative powder diffraction pattern analysis using the full pattern profile Barr, G., Gilmore, C. J., Paisley, J., J. Appl. Cryst. (2004). 37, 665–668 A longer reading list is here: http://www2.chem.gla.ac.uk/snap/PolySNAP_index.html You can find similar functionality in the panalytical software: The HighScore suite Thomas Degen, Mustapha Sadki, Egbert Bron, Uwe König and Gwilherm Nénert. Powder Diffraction, http://dx.doi.org/10.1017/S0885715614000840 A related development would be XRD-CT. This is computed tomography via powder diffraction by raster scanning a small beam across a large sample (and rotating). J. Appl. Cryst. (2014). 47, 1107-1117[ doi:10.1107/S1600576714008218 ] XRDUA: crystalline phase distribution maps by two-dimensional scanning and tomographic (micro) X-ray powder diffraction W. De Nolf, F. Vanmeert and K. Janssens It seems that the colours in resulting pictures are semi-quantitative, but perhaps not in the sense you had in mind. All the best, Jon On 13/11/2014 18:53, James Talbot wrote: 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 ++ Please do NOT attach files to the whole list alan.he...@neutronoptics.com Send commands to lists...@ill.fr eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++
Re: Statistics on semi-quantitative XRD data
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 ++ Please do NOT attach files to the whole list alan.he...@neutronoptics.com Send commands to lists...@ill.fr eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++
