Recent Changes for "Statistical Analysis (multiproxy studies)" - Climate Audit 101

Statistical Analysis (multiproxy studies)

Tillman — 2009-02-17 16:07:26

add NYT R article

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- 2). Steve McIntyre has provided [http://www.climateaudit.org/?page_id=372 Statistics and R], information about this popular open-source statistics software. "R is used a lot here and relearning basic stats with R will be big help if you become a regular at Climate Audit" [[http://www.climateaudit.org/?page_id=372 Russ]. Here is the link to the [http://www.r-project.org/ The R Project for Statistical Computing] to download this free software, available for Windows, Mac, and other platforms.	+ 2). Steve McIntyre has provided [http://www.climateaudit.org/?page_id=372 Statistics and R], information about this popular open-source statistics software. "R is used a lot here and relearning basic stats with R will be big help if you become a regular at Climate Audit" [[http://www.climateaudit.org/?page_id=372 Russ]. The New York Times has an [http://www.nytimes.com/2009/01/07/technology/business-computing/07program.html?_r=1&em=&pagewanted=all interesting 2009 article] on R. + + Here is the link to the [http://www.r-project.org/ The R Project for Statistical Computing] to download this free software, available for Windows, Mac, and other platforms.

Statistical Analysis (multiproxy studies)

Tillman — 2009-02-16 13:27:16

add a quote

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	+ And a useful cautionary reminder comes from statistician [http://www.climateaudit.org/?p=5238#comment-327909 David A. Freedman]: + "[S]tatistical technique can seldom be an adequate substitute for good design, relevant data, and testing predictions against reality in a variety of settings."

Statistical Analysis (multiproxy studies)

Tillman — 2008-11-03 21:40:56

Add Introduction to Multivariate Calibration

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- 4). Many of the problems CA and SM have identified involve '''misuse''' of valid statistical techniques. The primer here is Hans von Storch,	+ 4). [http://dbkgroup.org/WhitePapers/imc.htm An Introduction to Multivariate Calibration] is a good beginner's guide to such statistical methods as Principal Components Analysis and Partial Least Squares Regression. + + 5). Many of the problems CA and SM have identified involve '''misuse''' of valid statistical techniques. The primer here is Hans von Storch,
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- 5). Shumway & Stoffer's [http://www.stat.pitt.edu/stoffer/tsa2/index.html Time Series Analysis and Its Applications: With R Examples] is a resource for more advanced statistics do-it -yourselfers, especially those learning R.	+ 6). Shumway & Stoffer's [http://www.stat.pitt.edu/stoffer/tsa2/index.html Time Series Analysis and Its Applications: With R Examples] is a resource for more advanced statistics do-it -yourselfers, especially those learning R.

Statistical Analysis (multiproxy studies)

Tillman — 2008-02-05 13:36:20

add Misuses of statistical analysis in climate research.

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- 4). Shumway & Stoffer's [http://www.stat.pitt.edu/stoffer/tsa2/index.html Time Series Analysis and Its Applications: With R Examples] is a resource for more advanced statistics do-it -yourselfers, especially those learning R.	+ 4). Many of the problems CA and SM have identified involve '''misuse''' of valid statistical techniques. The primer here is Hans von Storch, + ''Misuses of statistical analysis in climate research'', online at http://coast.gkss.de/staff/storch/pdf/misuses.pdf . Unusually for technical statistics papers, it is quite readable and understandable by non-specialists. + + 5). Shumway & Stoffer's [http://www.stat.pitt.edu/stoffer/tsa2/index.html Time Series Analysis and Its Applications: With R Examples] is a resource for more advanced statistics do-it -yourselfers, especially those learning R.

Statistical Analysis (multiproxy studies)

Tillman — 2008-01-05 12:54:19

add kurtosis

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- ["Principal Component Analysis"] (PCA), technique used to reduce multidimensional data sets to (usually) two dimensions, for ease of analysis.	+ *[http://en.wikipedia.org/wiki/Kurtosis Kurtosis], statisical technique for determining "peakedness" of a distribution. "Flat kurtosis" means equal probability of any outcome; thus knowledge is insufficient to predict the outcome.
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- ["RE statistical test"], commonly used in ["Dendroclimatology"]	+ ["Principal Component Analysis"] (PCA), technique used to reduce multidimensional data sets to (usually) two dimensions, for ease of analysis. + + ["RE statistical test"], commonly used in ["Dendroclimatology"]

Statistical Analysis (multiproxy studies)

Tillman — 2008-01-04 22:53:21

revise BCP section

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- The Hockey Team has strenuously resisted efforts to "rein in" their addiction to BCPs, foxtail pines, and the ["strip-bark"] examples of both species. [http://www.climateaudit.org/?p=727 For example], {to be con'd-PT}	+ As [http://www.climateaudit.org/index.php?p=166 McKitrick notes], "If the flawed bristlecone pine series are removed [from ["MBH98"]], the hockey stick disappears regardless of how the PCs are calculated and regardless of how many are included. The hockey stick shape is not global, it is a local phenomenon associated with eccentric proxies." + + ===Climate Audit discussions of bristlecone pine proxies=== + [http://www.climateaudit.org/?p=727 NAS Panel #2: Bristlecones] + [http://www.climateaudit.org/?p=148 Bristlecone Pines Again] + *[http://www.climateaudit.org/?p=329 Bristlecone dC13]

Statistical Analysis (multiproxy studies)

GeorgeCastanza — 2007-12-26 21:20:52

minor edit, added some info, see Talk page

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- Many of the Team's manipulations are (or seem to be) designed to conceal the outsize weights the Mannian PCA technique places on the bristlecone pine (BCP) tree-ring "temperature" proxies. M&M have repeatedly demonstrated that when the BCP proxies are removed, the hockey-stick disappears, regardless of the statistical data manipulations used (or misused). [http://www.climateaudit.org/?p=933 For example], "Ross [McKitrick] and I categorically agree with Wahl and Ammann that an MBH-style reconstruction without bristlecones is non-meaningful. Our point of difference is that we assert that an MBH98-style reconstruction with bristlecones is also non-meaningful."	+ Many of the Team's questionable manipulations are related to the outsize weights the Mannian ["PCA"] technique places on the bristlecone pine (BCP) tree-ring proxies. Due to improper centering of the PCA, any proxy that has increased in variance in the 20th century will, essentially, dominate the weights of PC1 (at least), the most significant principal component ['''SEE DISCUSSION PAGE''']. M&M have repeatedly demonstrated that when the BCP proxies are removed, the hockey-stick disappears, regardless of the statistical data manipulations used (or misused). [http://www.climateaudit.org/?p=933 For example], "Ross [McKitrick] and I categorically agree with Wahl and Ammann that an MBH-style reconstruction without bristlecones is non-meaningful. Our point of difference is that we assert that an MBH98-style reconstruction with bristlecones is also non-meaningful."

Statistical Analysis (multiproxy studies)

Tillman — 2007-12-26 13:46:56

add Time Series Analysis and Its Applications: With R Examples

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	+ 4). Shumway & Stoffer's [http://www.stat.pitt.edu/stoffer/tsa2/index.html Time Series Analysis and Its Applications: With R Examples] is a resource for more advanced statistics do-it -yourselfers, especially those learning R. +
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	+ (just a start so far)

Statistical Analysis (multiproxy studies)

Tillman — 2007-12-26 13:27:38

add Engineering Statistics Handbook

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	+ + 3). The [http://www.itl.nist.gov/div898/handbook/index.htm Engineering Statistics Handbook] looks like a good resource to teach yourself statistical analysis.

Statistical Analysis (multiproxy studies)

Tillman — 2007-12-19 16:31:47

add intro; reco book; add Bristlecone pines, the Team's "Secret Sauce" (to be

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- {Describe Statistical Analysis (multiproxy studies) here.}	+ The M&M/CA criticisms of the Mannian "hockey stick" paleotemperature reconstructions are basically statistical in nature. In many cases the "Hockey Team" uses and misuses of statistics are (or appear to be) "window-dressing" or obfuscation of behind-the-scenes data manipulation to achieve a desired result. A useful primer is [http://en.wikipedia.org/wiki/How_to_Lie_with_Statistics How to Lie with Statistics], especially chapter 4, "Much Ado about Practically Nothing". This little volume, written in 1954, just might be the best introduction to statistics for the general reader. + + ==Bristlecone pines, the Team's "Secret Sauce"== + Many of the Team's manipulations are (or seem to be) designed to conceal the outsize weights the Mannian PCA technique places on the bristlecone pine (BCP) tree-ring "temperature" proxies. M&M have repeatedly demonstrated that when the BCP proxies are removed, the hockey-stick disappears, regardless of the statistical data manipulations used (or misused). [http://www.climateaudit.org/?p=933 For example], "Ross [McKitrick] and I categorically agree with Wahl and Ammann that an MBH-style reconstruction without bristlecones is non-meaningful. Our point of difference is that we assert that an MBH98-style reconstruction with bristlecones is also non-meaningful." + + The Hockey Team has strenuously resisted efforts to "rein in" their addiction to BCPs, foxtail pines, and the ["strip-bark"] examples of both species. [http://www.climateaudit.org/?p=727 For example], {to be con'd-PT}

Statistical Analysis (multiproxy studies)

Tillman — 2007-12-11 18:11:12

begin "Definitions of Statistical Terms" subsection; wikify links

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- 2). Steve McIntyre has provided [http://www.climateaudit.org/?page_id=372 Statistics and R], information about this popular open-source statistics software. "R is used a lot here and relearning basic stats with R will be big help if you become a regular at Climate Audit" [http://www.climateaudit.org/?page_id=372 Russ]. Here is the link to the [http://www.r-project.org/ The R Project for Statistical Computing] to download this free software, available for Windows, Mac, and other platforms.	+ 2). Steve McIntyre has provided [http://www.climateaudit.org/?page_id=372 Statistics and R], information about this popular open-source statistics software. "R is used a lot here and relearning basic stats with R will be big help if you become a regular at Climate Audit" [[http://www.climateaudit.org/?page_id=372 Russ]. Here is the link to the [http://www.r-project.org/ The R Project for Statistical Computing] to download this free software, available for Windows, Mac, and other platforms.
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	+ ===Definitions of Statistical Terms=== + + ["Principal Component Analysis"] (PCA), technique used to reduce multidimensional data sets to (usually) two dimensions, for ease of analysis. + + ["RE statistical test"], commonly used in ["Dendroclimatology"] + + [[br]]
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- http://www.climateaudit.org/?cat=18 , All threads in '''Statistics''' category	+ [http://www.climateaudit.org/?cat=18 All threads in "Statistics" category]
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- http://www.climateaudit.org/?cat=19 , All threads in '''Principal Components''' (["PCA"]) category	+ [http://www.climateaudit.org/?cat=19 All threads in "Principal Components" (["PCA"]) category]
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- http://www.climateaudit.org/?cat=11 , All threads in '''Spurious''' statistics category	+ [http://www.climateaudit.org/?cat=11 All threads in "Spurious" statistics category]
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- http://www.climateaudit.org/?p=2418 , Ross McKitrick on Mann et al 2007 : PC error, significance of RE, CE and r2 tests, misuse of ["RegEM"]	+ [http://www.climateaudit.org/?p=2418 Ross McKitrick on Mann et al 2007] : PC error, significance of RE, CE and r2 tests, misuse of ["RegEM"]
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- http://www.climateaudit.org/?p=2419 , Re-Visiting RegEM: Rutherford et al 2005	+ [http://www.climateaudit.org/?p=2419 Re-Visiting RegEM: Rutherford et al 2005]

Statistical Analysis (multiproxy studies)

Tillman — 2007-12-11 16:49:54

start section, Statistical Analysis Threads at Climate Audit

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- 1). "This blog is based on statistics. My feeling is that people who want to understand should make some effort to look up the theory (and believe me, basic statistics is not difficult), before asking for help from others. The theory is couched in jargon, as in all specialty fields." [http://www.climateaudit.org/?p=2448 MarkR, post #92] A good place to start is [http://en.wikipedia.org/wiki/Statistics the Wikipedia introduction to statistics].	+ 1). "This blog is based on statistics. My feeling is that people who want to understand should make some effort to look up the theory (and believe me, basic statistics is not difficult), before asking for help from others. The theory is couched in jargon, as in all specialty fields." [http://www.climateaudit.org/?p=2448 MarkR, post #92]. A good place to start is [http://en.wikipedia.org/wiki/Statistics the Wikipedia introduction to statistics].
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	+ + ==Statistical Analysis Threads at Climate Audit== + + http://www.climateaudit.org/?cat=18 , All threads in '''Statistics''' category + + http://www.climateaudit.org/?cat=19 , All threads in '''Principal Components''' (["PCA"]) category + + http://www.climateaudit.org/?cat=11 , All threads in '''Spurious''' statistics category + + [[br]] + http://www.climateaudit.org/?p=2418 , Ross McKitrick on Mann et al 2007 : PC error, significance of RE, CE and r2 tests, misuse of ["RegEM"] + + http://www.climateaudit.org/?p=2419 , Re-Visiting RegEM: Rutherford et al 2005

Statistical Analysis (multiproxy studies)

Tillman — 2007-12-09 16:06:41

create "Basic Statistics for Climate Audit readers"

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- Describe Statistical Analysis (multiproxy studies) here.	+ {Describe Statistical Analysis (multiproxy studies) here.} + + ==Basic Statistics for Climate Audit readers== + Probably no other area of Climate Audit is harder to follow for nonspecialists than the statistical discussions. There isn't any real shortcut to understanding statistics. This writer recalls struggling with the topic in graduate school -- it would take me working through a statistical problem three times to really understand what was going on. And most of this hard-won knowledge is now lost with disuse and the passing of years. + + That said, here are some resources to help you learn (or relearn) the statistics used at Climate Audit: + + 1). "This blog is based on statistics. My feeling is that people who want to understand should make some effort to look up the theory (and believe me, basic statistics is not difficult), before asking for help from others. The theory is couched in jargon, as in all specialty fields." [http://www.climateaudit.org/?p=2448 MarkR, post #92] A good place to start is [http://en.wikipedia.org/wiki/Statistics the Wikipedia introduction to statistics]. + + 2). Steve McIntyre has provided [http://www.climateaudit.org/?page_id=372 Statistics and R], information about this popular open-source statistics software. "R is used a lot here and relearning basic stats with R will be big help if you become a regular at Climate Audit" [http://www.climateaudit.org/?page_id=372 Russ]. Here is the link to the [http://www.r-project.org/ The R Project for Statistical Computing] to download this free software, available for Windows, Mac, and other platforms.

Statistical Analysis (multiproxy studies)

GeorgeCastanza — 2007-11-30 22:01:25

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Statistical Analysis (multiproxy studies)

GeorgeCastanza — 2007-11-30 19:38:13

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	+ Describe Statistical Analysis (multiproxy studies) here.