Re: Interesting links (in my opinion)

[Edward Boadi]

Hi Marta,
I am interested in buying the following books "Statistics at Square One"
and "Research Methods II: Multivariate Analysis" .

I will be happy if you can advice on where I could get them.

Regards.

-----Original Message-----
From: SPSSX(r) Discussion [mailto:[hidden email]]On Behalf Of
Marta García-Granero
Sent: Thursday, June 29, 2006 12:17 PM
To: [hidden email]
Subject: Interesting links (in my opinion)


Hi everybody:

Since a lot of questions to this list concern theoretical issues, I
thought that these links could be interesting for a lot of people. The
first one reviews basic stats, while the second focuses on more
advanced methods.

Statistics at Square One
=========================
1 Data display and summary
2 Mean and standard deviation
3 Populations and samples
4 Statements of probability and confidence intervals
5 Differences between means: type I and type II errors and power
6 Differences between percentages and paired alternatives
7 The t tests
8 The chi-squared tests
9 Exact probabilty test
10 Rank score tests
11 Correlation and regression
12 Survival analysis
13 Study design and choosing a statistical test

Available as on-line book (HTML) at:
http://bmj.bmjjournals.com/collections/statsbk/index.shtml

SPSS syntax code (written by me and kindly hosted by King Douglas) for
the book exercises and examples is available at:
http://www.kingdouglas.com/SPSS/DiverseCultures/Marta/Code/BMJ%20-%20Stats%20Square%20One.txt
(if the link is broken in two by my mail program, copy and paste both
pieces together...)

------------------------------------------------------------------------
Research Methods II: Multivariate Analysis
============================================
Chapter 1: The Scientific Method
Chapter 2: Simple Linear Regression
Chapter 3: Multiple Regression Analysis
Chapter 4: Multiple Regression in Practice
Chapter 5: Regression Diagnostics
Chapter 6: Analysis of Cross-Sectional Studies
Chapter 7: One-way Analysis of Variance
Chapter 8: Two-way Analysis of Variance
Chapter 9: Factorial Designs
Chapter 10: Repeat-measures Designs
Chapter 11: Logistic Regression
Chapter 12: Survival Analysis
Chapter 13: Poisson Regression Analysis
Chapter 14: Analysing Categorical Data: Log-linear analysis

Available as on-line book (PDF) at:

http://www.oxfordjournals.org/tropej/online/ma.html
(they also have a collection of PowerPoint slides for each chapter)

Although I haven't written SPSS code for the second book (I just
discovered it today!), give me some time and (after my holidays), I'll
have it available.


I hope you find them useful.

Marta

[Marta García-Granero]

Hi Edward

EB> I am interested in buying the following books "Statistics at Square One"
EB> and "Research Methods II: Multivariate Analysis" .

These are on-line books... As a matter of fact, I don't think the
second one exists in hard copy (unless you take the time to download
every pdf file and print them, as I did).
http://www.oxfordjournals.org/tropej/online/ma.html

The first one, Statistics at Square One, can be viewed on line too
http://bmj.bmjjournals.com/collections/statsbk/index.shtml
Until I bought it, I made the effort of printing to PDF every chapter
and putting all chapter together in one single file. It's quite easy
(if you have Acrobat PDF Writer installed in you computer).

A printed version (10th edition, instead of 9th edition, the one on line)
can be bought at BMJ e-store:
http://www.bmjbookshop.com/shop/product_display.asp?&SiteLanguage=ENG&productid=0727915525

Once there, if you are really insterested in buying books, then take a
look also at "Statistics at Square Two" (I bought it too, quite good)


Regards,
Marta

EB> -----Original Message-----
EB> From: SPSSX(r) Discussion [mailto:[hidden email]]On Behalf Of
EB> Marta García-Granero
EB> Sent: Thursday, June 29, 2006 12:17 PM
EB> To: [hidden email]
EB> Subject: Interesting links (in my opinion)

EB> Hi everybody:

EB> Since a lot of questions to this list concern theoretical issues, I
EB> thought that these links could be interesting for a lot of people. The
EB> first one reviews basic stats, while the second focuses on more
EB> advanced methods.

EB> Statistics at Square One
EB> =========================
EB> 1 Data display and summary
EB> 2 Mean and standard deviation
EB> 3 Populations and samples
EB> 4 Statements of probability and confidence intervals
EB> 5 Differences between means: type I and type II errors and power
EB> 6 Differences between percentages and paired alternatives
EB> 7 The t tests
EB> 8 The chi-squared tests
EB> 9 Exact probabilty test
EB> 10 Rank score tests
EB> 11 Correlation and regression
EB> 12 Survival analysis
EB> 13 Study design and choosing a statistical test

EB> Available as on-line book (HTML) at:
EB> http://bmj.bmjjournals.com/collections/statsbk/index.shtml

EB> SPSS syntax code (written by me and kindly hosted by King Douglas) for
EB> the book exercises and examples is available at:
EB> http://www.kingdouglas.com/SPSS/DiverseCultures/Marta/Code/BMJ%20-%20Stats%20Square%20One.txt
EB> (if the link is broken in two by my mail program, copy and paste both
EB> pieces together...)

EB> ------------------------------------------------------------------------
EB> Research Methods II: Multivariate Analysis
EB> ============================================
EB> Chapter 1: The Scientific Method
EB> Chapter 2: Simple Linear Regression
EB> Chapter 3: Multiple Regression Analysis
EB> Chapter 4: Multiple Regression in Practice
EB> Chapter 5: Regression Diagnostics
EB> Chapter 6: Analysis of Cross-Sectional Studies
EB> Chapter 7: One-way Analysis of Variance
EB> Chapter 8: Two-way Analysis of Variance
EB> Chapter 9: Factorial Designs
EB> Chapter 10: Repeat-measures Designs
EB> Chapter 11: Logistic Regression
EB> Chapter 12: Survival Analysis
EB> Chapter 13: Poisson Regression Analysis
EB> Chapter 14: Analysing Categorical Data: Log-linear analysis

EB> Available as on-line book (PDF) at:

EB> http://www.oxfordjournals.org/tropej/online/ma.html
EB> (they also have a collection of PowerPoint slides for each chapter)

EB> Although I haven't written SPSS code for the second book (I just
EB> discovered it today!), give me some time and (after my holidays), I'll
EB> have it available.


EB> I hope you find them useful.

[Mark Webb-3]

Is the second book available on-line like the first ?
Or only in print format ?

Regards
Mark

----- Original Message -----
From: "Marta García-Granero" <[hidden email]>
To: <[hidden email]>
Sent: Wednesday, September 13, 2006 9:06 AM
Subject: Re: Interesting links (in my opinion)

> Hi Edward
>
> EB> I am interested in buying the following books "Statistics at Square
> One"
> EB> and "Research Methods II: Multivariate Analysis" .
>
> These are on-line books... As a matter of fact, I don't think the
> second one exists in hard copy (unless you take the time to download
> every pdf file and print them, as I did).
> http://www.oxfordjournals.org/tropej/online/ma.html
>
> The first one, Statistics at Square One, can be viewed on line too
> http://bmj.bmjjournals.com/collections/statsbk/index.shtml
> Until I bought it, I made the effort of printing to PDF every chapter
> and putting all chapter together in one single file. It's quite easy
> (if you have Acrobat PDF Writer installed in you computer).
>
> A printed version (10th edition, instead of 9th edition, the one on line)
> can be bought at BMJ e-store:
> http://www.bmjbookshop.com/shop/product_display.asp?&SiteLanguage=ENG&productid=0727915525
>
> Once there, if you are really insterested in buying books, then take a
> look also at "Statistics at Square Two" (I bought it too, quite good)
>
>
> Regards,
> Marta
>
> EB> -----Original Message-----
> EB> From: SPSSX(r) Discussion [mailto:[hidden email]]On Behalf
> Of
> EB> Marta García-Granero
> EB> Sent: Thursday, June 29, 2006 12:17 PM
> EB> To: [hidden email]
> EB> Subject: Interesting links (in my opinion)
>
> EB> Hi everybody:
>
> EB> Since a lot of questions to this list concern theoretical issues, I
> EB> thought that these links could be interesting for a lot of people. The
> EB> first one reviews basic stats, while the second focuses on more
> EB> advanced methods.
>
> EB> Statistics at Square One
> EB> =========================
> EB> 1 Data display and summary
> EB> 2 Mean and standard deviation
> EB> 3 Populations and samples
> EB> 4 Statements of probability and confidence intervals
> EB> 5 Differences between means: type I and type II errors and power
> EB> 6 Differences between percentages and paired alternatives
> EB> 7 The t tests
> EB> 8 The chi-squared tests
> EB> 9 Exact probabilty test
> EB> 10 Rank score tests
> EB> 11 Correlation and regression
> EB> 12 Survival analysis
> EB> 13 Study design and choosing a statistical test
>
> EB> Available as on-line book (HTML) at:
> EB> http://bmj.bmjjournals.com/collections/statsbk/index.shtml
>
> EB> SPSS syntax code (written by me and kindly hosted by King Douglas) for
> EB> the book exercises and examples is available at:
> EB>
> http://www.kingdouglas.com/SPSS/DiverseCultures/Marta/Code/BMJ%20-%20Stats%20Square%20One.txt
> EB> (if the link is broken in two by my mail program, copy and paste both
> EB> pieces together...)
>
> EB> ------------------------------------------------------------------------
> EB> Research Methods II: Multivariate Analysis
> EB> ============================================
> EB> Chapter 1: The Scientific Method
> EB> Chapter 2: Simple Linear Regression
> EB> Chapter 3: Multiple Regression Analysis
> EB> Chapter 4: Multiple Regression in Practice
> EB> Chapter 5: Regression Diagnostics
> EB> Chapter 6: Analysis of Cross-Sectional Studies
> EB> Chapter 7: One-way Analysis of Variance
> EB> Chapter 8: Two-way Analysis of Variance
> EB> Chapter 9: Factorial Designs
> EB> Chapter 10: Repeat-measures Designs
> EB> Chapter 11: Logistic Regression
> EB> Chapter 12: Survival Analysis
> EB> Chapter 13: Poisson Regression Analysis
> EB> Chapter 14: Analysing Categorical Data: Log-linear analysis
>
> EB> Available as on-line book (PDF) at:
>
> EB> http://www.oxfordjournals.org/tropej/online/ma.html
> EB> (they also have a collection of PowerPoint slides for each chapter)
>
> EB> Although I haven't written SPSS code for the second book (I just
> EB> discovered it today!), give me some time and (after my holidays), I'll
> EB> have it available.
>
>
> EB> I hope you find them useful.
>
> __________ NOD32 1.1753 (20060912) Information __________
>
> This message was checked by NOD32 antivirus system.
> http://www.eset.com
>
>

[Edward Boadi]

Thank you , Marta & Angshu .

-----Original Message-----
From: SPSSX(r) Discussion [mailto:[hidden email]]On Behalf Of
Marta García-Granero
Sent: Wednesday, September 13, 2006 3:06 AM
To: [hidden email]
Subject: Re: Interesting links (in my opinion)


Hi Edward

EB> I am interested in buying the following books "Statistics at Square One"
EB> and "Research Methods II: Multivariate Analysis" .

These are on-line books... As a matter of fact, I don't think the
second one exists in hard copy (unless you take the time to download
every pdf file and print them, as I did).
http://www.oxfordjournals.org/tropej/online/ma.html

The first one, Statistics at Square One, can be viewed on line too
http://bmj.bmjjournals.com/collections/statsbk/index.shtml
Until I bought it, I made the effort of printing to PDF every chapter
and putting all chapter together in one single file. It's quite easy
(if you have Acrobat PDF Writer installed in you computer).

A printed version (10th edition, instead of 9th edition, the one on line)
can be bought at BMJ e-store:
http://www.bmjbookshop.com/shop/product_display.asp?&SiteLanguage=ENG&productid=0727915525

Once there, if you are really insterested in buying books, then take a
look also at "Statistics at Square Two" (I bought it too, quite good)


Regards,
Marta

EB> -----Original Message-----
EB> From: SPSSX(r) Discussion [mailto:[hidden email]]On Behalf Of
EB> Marta García-Granero
EB> Sent: Thursday, June 29, 2006 12:17 PM
EB> To: [hidden email]
EB> Subject: Interesting links (in my opinion)

EB> Hi everybody:

EB> Since a lot of questions to this list concern theoretical issues, I
EB> thought that these links could be interesting for a lot of people. The
EB> first one reviews basic stats, while the second focuses on more
EB> advanced methods.

EB> Statistics at Square One
EB> =========================
EB> 1 Data display and summary
EB> 2 Mean and standard deviation
EB> 3 Populations and samples
EB> 4 Statements of probability and confidence intervals
EB> 5 Differences between means: type I and type II errors and power
EB> 6 Differences between percentages and paired alternatives
EB> 7 The t tests
EB> 8 The chi-squared tests
EB> 9 Exact probabilty test
EB> 10 Rank score tests
EB> 11 Correlation and regression
EB> 12 Survival analysis
EB> 13 Study design and choosing a statistical test

EB> Available as on-line book (HTML) at:
EB> http://bmj.bmjjournals.com/collections/statsbk/index.shtml

EB> SPSS syntax code (written by me and kindly hosted by King Douglas) for
EB> the book exercises and examples is available at:
EB> http://www.kingdouglas.com/SPSS/DiverseCultures/Marta/Code/BMJ%20-%20Stats%20Square%20One.txt
EB> (if the link is broken in two by my mail program, copy and paste both
EB> pieces together...)

EB> ------------------------------------------------------------------------
EB> Research Methods II: Multivariate Analysis
EB> ============================================
EB> Chapter 1: The Scientific Method
EB> Chapter 2: Simple Linear Regression
EB> Chapter 3: Multiple Regression Analysis
EB> Chapter 4: Multiple Regression in Practice
EB> Chapter 5: Regression Diagnostics
EB> Chapter 6: Analysis of Cross-Sectional Studies
EB> Chapter 7: One-way Analysis of Variance
EB> Chapter 8: Two-way Analysis of Variance
EB> Chapter 9: Factorial Designs
EB> Chapter 10: Repeat-measures Designs
EB> Chapter 11: Logistic Regression
EB> Chapter 12: Survival Analysis
EB> Chapter 13: Poisson Regression Analysis
EB> Chapter 14: Analysing Categorical Data: Log-linear analysis

EB> Available as on-line book (PDF) at:

EB> http://www.oxfordjournals.org/tropej/online/ma.html
EB> (they also have a collection of PowerPoint slides for each chapter)

EB> Although I haven't written SPSS code for the second book (I just
EB> discovered it today!), give me some time and (after my holidays), I'll
EB> have it available.


EB> I hope you find them useful.

[cbautista]

Hi all,

Using Cox regression analysis, I'd like to estimate the p-value for each
correlation reported on the correlation matrix of regression coefficients.
How Can I do that?

Thanks,

/Christian

[Marta García-Granero]

Hi Christian

The correlation matrix you mention is used only to estimate CI for HR for
individuals/groups with certain covariate patterns, I think it is not very
useful to know whether they are significant or not. As a matter of
fact, you must use CONVERT to turn it into a Variances/covariances
matrix (the one you really use for CI estimation).

What on earth do you need those p-values for? ;)

CB> Using Cox regression analysis, I'd like to estimate the p-value for each
CB> correlation reported on the correlation matrix of regression coefficients.


--
Regards,
Dr. Marta García-Granero,PhD           mailto:[hidden email]
Statistician

---
"It is unwise to use a statistical procedure whose use one does
not understand. SPSS syntax guide cannot supply this knowledge, and it
is certainly no substitute for the basic understanding of statistics
and statistical thinking that is essential for the wise choice of
methods and the correct interpretation of their results".

(Adapted from WinPepi manual - I'm sure Joe Abrahmson will not mind)

[Marta García-Granero]

Hi Christian

Now I understand... I think the authors have the concept wrong, they
meant to talk about the correlation matrix of predictors (not the
correlation matrix of regression coefficients). At least, the
phenomenon they discuss (..."higher proportion of young HCC patients
were male"...) is simply an association (correlation) between both
predictors (age and sex). They wrongly call that "an interaction",
when they should discuss it in terms of "multicollinearity".

Interaction in this context (Cox regression model) would mean that the
effect of age on survival of HCC patients depends on gender (and vice
versa): the HR of age would be different for males and females. Here
they are simply talking about association between predictors, and
calling it - wrongly - interaction of predictors. As a matter of fact,
those associations they talk about could be related to confounding,
and the discussion of the paper is foccused mainly on confounding
(although, since they don't know the concept, they don't call it that
way).

It astounds me that the reviewers of the paper didn't correct it
before printing (I bet that none were statisticians nor
epidemiologists...). I'm going to keep this paper for my "gallery of
horrors", and I'll discuss it with my students this year.

I hope it's all clear now, but if you need more help, I can be reached
here (at the list), I check my mail quite often (as a matter of fact,
so often that my husband thinks I'm hooked on this list...)

Monday, September 18, 2006, 10:59:10 PM, You wrote:

cho> See page 3, section

cho> Interaction Between Age, Gender and HBsAg

cho> In our previous study, we found that on analyzing the correlation matrix of
cho> regression coefficients in the multivariate
cho> analysis, there were interactions between HBsAg and gender (r=-0.205,
cho> P<0.001) and age (r=0.166, P<0.001).[6] As
cho> shown in Table 4 , a higher proportion of young HCC patients was male
cho> gender. 83.7% of HCC patients below 40
cho> years of age were male, while 79.1% of HCC patients older than 40 years of
cho> age were male (P < 0.001). In addition,
cho> young HCC patients were more likely to be HBV carriers. 89.8% of young HCC
cho> patients had positive HBsAg. In
cho> contrast, only 59.1% of HCC patients older than 40 years of age had
cho> positive HBsAg (P < 0.001).


--
Regards,
Dr. Marta García-Granero,PhD           mailto:[hidden email]
Statistician

---
"It is unwise to use a statistical procedure whose use one does
not understand. SPSS syntax guide cannot supply this knowledge, and it
is certainly no substitute for the basic understanding of statistics
and statistical thinking that is essential for the wise choice of
methods and the correct interpretation of their results".

(Adapted from WinPepi manual - I'm sure Joe Abrahmson will not mind)