When and Why not to take arithmetic averages

Correlation coefficients, coefficients of variations, standard deviations, slopes, tangents, cosines, densities, temperatures, dissimilar ratios, and intensive properties in general are not additive. Therefore, arithmetic averages cannot be computed out of any of these.

Still, from time to time some “experts” and pseudo “scientists” do that.

Want to know why this is not mathematically and statistically possible? This is the subject of a paper I wrote and that is about to be published in Communications in Statistics – Theory and Methods (by Taylor & Francis).

Incidentally, I will provide a preview of the topic to the search marketing community. Thanks to my dear friend, Mike Grehan, this will be the topic I’ll be speaking about at the March, 2012 SES, NY.

l’Hopital’s Rule and the 0^0 Power Controversy

I’m currently working on some nice formulas that require l’Hopital’s Rule (sometimes written as l’Hospital (with the “s” silent. The “o” also goes with a “hat”) and came across a note from Professor Stephen A. Fulling, in which he mentions the never-ending zero-to-the zero power controversy.

Not even mathematicians agree on what the result should be. It has been argued that the answer is a matter of convenience, an element controversial -if not contrary- to Mathematics. What’s your take on the issue?

To learn more about this rule and when it should be applied, see Wikipedia or WolframMathWorld.

My IPAM Lost Pictures

On January 23-27, 2006 I was at the Institute for Pure and Applied Mathematics, UCLA, California attending a now infamous Document Space Workshop. I took some pictures, but did not find these until now.

I’ve posted these in my facebook page, posing with back then IPAM director and with world-recognized LSI expert Dr. Michael Berry and his former students. To learn more about the workshop and the speakers, follow this link http://www.miislita.com/ipam/ipam-document-space-workshop.pdf

Accessing Wikipedia Today

I have no problem accessing and navigating the spanish version of wikipedia (http://es.wikipedia.org/wiki/Wikipedia:Portada ). Ha. That much for their Internet “block” Dark Day.

 

Happy New Year!

We wish you all a great data mining 2012.

 

 

A New Weighting Strategy

I received this morning from the editors of Communications in Statistics: Theory and Methods confirmation that they accepted and will be publishing my peer reviewed paper on a new model for statistical analysis. It should be out this 2012.

Once published, you will understand the SEO (* SEOmoz, I should say) non-sense of computing arithmetic averages of correlation coefficients and why some meta-analysis studies published in the past (* Hunter-Schmidt; Hedges-Olkin) are flawed and invalid.

It took me several meals and research hours to figure it out. I hope that IRs, dataminers, and statistics colleagues find new applications for the model.

The model can be applied to many fields, including marketing, business, risk analysis, data mining, signal processing, engineering, clinical trials, and almost any field or knowledge domain that involves the calculation of weighted statistics. I look forward to discuss it online once it get published.

Happy New Year.

PS. (*) I’ve edited this post to make these points obvious. So, the issue of arithmetically averaging correlations has been raised and killed for good before the scientific and statistical community.

PS. Just in: Last night (Jan-03-2012) I received news from one of the editors of the journal that the paper was assigned to issue 41 (8). Check for its title: The Self-Weighting Model (in Spanish is something like “El Modelo de Autoponderacion“. I forget to mention that this journal is published biweekly; so, things are moving fast. What a way of ending 2011 and starting 2012!!!

Merry Christmas: the google hacking way

Yesterday we had a brainstorming session with our programmers on google hacking. It is soooooo easy to grab php codes, passwords, databases from all over the Web, thanks to sloppy coders. For instance, do a search for

index.of
index.of/php
index.of/pswd
index.of/db
index.of/mda
index.of/pgp

or check the list at http://www.thenetworkadministrator.com/googlesearches.htm These types of searches will spit out directory trees.

There are many “smart cookies” posting derivatives of these lists all over the Web.

And how about typos?

Try filetype command searches with extra characters in extensions like

0php
1php
phps
php.

etc….

Servers will spit out entire php codes.

The great offenders are large sites like those belonging to .edu, .gov, .org, not to mention large .com and .net sites.

Ho, Ho, Ho, Merry Christmas, Santa.

Google early years and LSI

For years many SEOs fooled their own peers with the assertion that LSI was something new that Google implemented. Some even have claimed LSI was a proprietary algorithm from Google. I’ve spent sooooo many years debunking all this crap and few other urban legends from unscrupulous SEOs.

In this Thanksgiving Day I thank that all these myths have been debunked to no end: LSI-rank correlations, LDA-rank correlations, KD-rank correlations, additiveness of correlation coefficients, blah, blah, blah…  I thank also that along came this: http://infolab.stanford.edu/~sergey/349/

LSI?

Known from the onset by Google.

A cost effective implementation in a large scale and dynamic environment as the Web is?

Nope.

Our Whois Miner is Getting Smarter

Welcome to the new and improved interface of Minerazzi’s Whois Miner (beta).

The Whois Miner is getting smarter. It now gives you the alternate name of a whois server service. It also has network mining features, enabling you to mine registrant DNS lookups, Headers, NS/MX records, and contact emails.

In addition, we keep expanding our index of whois servers. Follow link below.

Use it for free while you can.

http://www.minerazzi.com/labs/whois.php

Play with it and send some feedback.

New Whois User Interface

Last night we uploaded a new user interface (UI) for the Minerazzi Multiple Whois Miner (http://www.minerazzi.com/labs/whois.php).

 

Added support to:

1. generic third-level domains (gTLDs).

2. country-code TLDs.

3. subdomain TLDs.

4. status persistency of form fields (without using cookies, sessions, JavaScript, but just pure PHP).

 

As we keep improving and adding new TLDs and whois servers to its index, we expect this to become a destination for our regular users.

The tool was designed in such a way that even support to the upcoming dotBrand Revolution is possible.

 

Enjoy it