Wednesday, December 9, 2009

What are the zettabytes?

An interesting study about the information consumed in U.S.

"In 2008, Americans consumed information for about 1.3 trillion hours, an average of almost 12 hours per day. Consumption totaled 3.6 zettabytes and 10,845 trillion words, corresponding to 100,500 words and 34 gigabytes for an average person on an average day. A zettabyte is 10 to the 21st power bytes, a million million gigabytes. These estimates are from an analysis of more than 20 different sources of information, from very old (newspapers and books) to very new (portable computer games, satellite radio, and Internet video).

Video sources (moving pictures) dominate bytes of information, with 1.3 zettabytes from television and approximately 2 zettabytes of computer games. If hours or words are used
as the measurement, information sources are more widely distributed, with substantial amounts from radio, Internet browsing, and others. All of our results are estimates.

Previous studies of information have reported much lower quantities. Two previous How Much
Information? studies, by Peter Lyman and Hal Varian in 2000 and 2003, analyzed the quantity of original content created, rather than what was consumed. A more recent study measured consumption, but estimated that only .3 zettabytes were consumed worldwide in 2007.
Hours of information consumption grew at 2.6 percent per year from 1980 to 2008, due to a combination of population growth and increasing hours per capita, from 7.4 to 11.8. More surprising is that information consumption in bytes increased at only 5.4 percent per year. Yet the capacity to process data has been driven by Moore’s Law, rising at least 30 percent per year.

One reason for the slow growth in bytes is that color TV changed little over that period. High-definition TV is increasing the number of bytes in TV programs, but slowly.
The traditional media of radio and TV still dominate our consumption per day, with a total of 60 percent of the hours. In total, more than three-quarters of U.S. households’ information time is spent with noncomputer sources. Despite this, computers have had major effects on some aspects of information consumption. In the past, information consumption was overwhelmingly passive, with telephone being the only interactive medium.

Thanks to computers, a full third of words and more than half of bytes are now received interactively.

Reading, which was in decline due to the growth of television, tripled from 1980 to 2008, because it is theoverwhelmingly preferred way to receive words on the Internet."

Tuesday, December 8, 2009

Google is moving into Real-Time search

I am quite impressed of what google is doing in the real-time field, where they claim the monitor about 1 billion of fast moving urls.

Monday, December 7, 2009

Yahoo! and Microsoft cement 10-year search deal

Yahoo! and Microsoft have finalised the terms of their search agreement, five months after announcing the deal.

From The Telegraph
"Microsoft’s Bing and Yahoo! search are pooling their efforts in order to try and take on the dominance of Google in the search market. According to Net Applications’ most recent global figures, Google accounted for 85 per cent of all searches, while Bing took 3.3 per cent share and Yahoo! search accounted for 6.22 per cent of the total market. "

Sunday, December 6, 2009

Inverting a matrix?

Can you leverage the techiques of yesterday's question to invert a matrix?

Saturday, December 5, 2009

Dividing a number with no division

This could be an interview question, but do not expect me to ask this question anymore ;-)

"Given a>0 can you compute a^-1 without any division?"

Friday, December 4, 2009

Google Customizes More of Its Search Results

This is an important step for Google and I do appreciate the initiative. Personalized search has been one of the hot topic in the academia, with a lot of people trying to obtain a personalized version of page rank. Well, personalization is more about Dynamic ranking and not about Static ranking. Other search engines are also adopting personalized forms of ranking, but here google is raising the bar..

"For many of its users, Google offers Web search results that are customized based on their previous search history and clicks. For example, if someone consistently favors a particular sports site, Google will put that site high in the results when they look up sports topics in its search engine.

But there has always been one catch: people had to be signed in to a Google account to see such customization.

On Friday Google said it was extending these personalized search results to people who are not logged into the service."

Thursday, December 3, 2009

Quoting Wikipedia, which cites me and Alessio

This is a study that Alessio and me carried out back in 2004. Alessio is now Director of Search, Oneriot the Realt Time search engine beyond Yahoo!. Wikipedia is now citing us.

A more recent study, which used Web searches in 75 different languages to sample the Web, determined that there were over 11.5 billion Web pages in the publicly indexable Web as of the end of January 2005.[61]


Wednesday, December 2, 2009

Search capitalization


This is a one year comparison about market capitalization on 1 Dec 2009. I used Apple as benchmark since that tech stock had a great performance this year.

Tuesday, December 1, 2009

Web Search signals

Search Engine Watch just published an article about 'new' search signals. Well, I don't believe these are new signals since they are quite well discussed in already published seach patents (seo by the sea is a great source for search patents). In addition, query session data analysis is missing in the list and that is another very important class of signals.

Monday, November 30, 2009

Minimize a quadratic function

How to minimize the quadratic function f(x) = 1/2 x^T A x + b^T x + c, subject to the constrain Vx=d, where T is the usual transpose operator, A is a matrix, and b, c, d are vectors?

Pretty elegant application of Karush–Kuhn–Tucker conditions

Sunday, November 29, 2009

Vivisimo, SnakeT, Ask, Bing and now Google side bar

Vivisimo and SnakeT experimented with it. Bing made it for real. Ask3d proposed it and then left to become more Google like. Now google wants to be similar to Ask3d and Bing. Quoting pandia. Life is a circle. In any case, the Categorized search with automatically generated sidebar proposal was an important part of my Ph.D thesis, back in 2004-2005. This is about being a bit early than others. SnakeT is no longer maintained but still working back from the university days.

"Unlike Bing and Yahoo, Google does not have a permanent left hand sidebar with additional links for more narrow searches. Instead there is a link at the top of the page called “Show options”.

Click on it and Google will add a sidebar which helps you refine your search query. You may, for instance, limit your search to new pages from the last hour.

Search Engine Land reports that Google will change it’s search result pages next year and give them a more coherent look and feel.

Most importantly: It seems the sidebar will become a permanent feature on all search result pages.

Google sidebar

The sidebar will include links to Images, News, Books, Maps and “More”, as well as related searches and links that let you limit the search to a specific time period.

Google will give you the alternatives (or “modes”) it thinks is most relevant to your search.

Ask.com launched search result pages like this in 2007. Because of this Ask.com became one of our favorite search engines. Ask later abandoned its “3D” search in order to become more like Google!"



Saturday, November 28, 2009

Friday, November 27, 2009

Thursday, November 26, 2009

Search Layers

Search Engines tend to organize indexes in layers. The intuition is that: If "enough good" documents are retrieved from the i-th layer, then you don't need to go to the (i+1)-th layer. Questions:

1. how do you partition the documents?
2. what is "good"?
3. what is "enough"?

Please formalize your answers.

Wednesday, November 25, 2009

Distribution of Facebook Users (~300M world wide)


Facebook claims that they have more than 300 Million of users world wide. I sampled their ads user database and found the following geographical users' distribution:
  1. 34.32% are in U.S.
  2. 8.15% are in U.K.
  3. 5.05% are in France
  4. 4.99% are in Canada
  5. 4.50% are in Italy
  6. 4.42% are in Indonesia
  7. 2.65% are in Spain
Here you can find the distribution of all the other nations.

Monday, November 23, 2009

Weights and Scale: a variation.

You have 6 weights which appears almost identical but 3 of them are slightly heavier than the remaining 3. The 6 weigth have 3 colours: red, green and blue. For each colour there is a pair of weights and one of the weight in the pair is slighlty heavier than the other. How many times do you need to use a scale with two plates for identifying the lighter weights?

Sunday, November 22, 2009

Ranking teams

Suppose that you have N teams playing a football league. Each team has a rank r_i parameter> 0 and assume there are no ties. Questions:
  1. What is the probability for team i to win on team j?
  2. What is the probability of the whole season (each team plays against the remaining ones)?
  3. Find an algorithm to rank the teams
Please provide your ideas.

Saturday, November 21, 2009

Random Decision Trees

Random Decision Trees are an interesting variant of Decision Trees. Here the key elements:
  1. Different training sets are generated from the N objects in the original training set, by using a bootstrap procedure which randomly samples the same example multiple times. Each sample generate a different tree and all the trees are seen as a forest;
  2. The random trees classifier takes the input feature vector, classifies it with every tree in the forest, and outputs the class label that recieved the majority of “votes”.
  3. Each node of each tree is trained on a random subset of the variables. The size of this set is a training parameter (in general sqrt(#features)). The best split criterium is chosen just considering the random sampled variables;
  4. Due to the above random selection, some training elements are left out for evaluation. In particular, for each left-out vector, find the the class that has got the majority of votes in the trees and compare it to the ground-truth response.
  5. Classification error estimate is computed as ratio of number of misclassified left-out vectors to all the vectors in the original data.
As you know, I love the idea of Boosting (such as AdaBoost) and the ideas behind Random Decision Trees are quite intriguing too.

Friday, November 20, 2009

Bing UK -- Out Of Beta Tag For Handling Search Overload In The UK

Nice article here

It is true that Internet has drastically grown in the past few years and has become more complex, but Search Engines are still on the verge of evolution. In order to make search engines more reliable information resource for users, Microsoft launched Bing in June, 2009.

Bing was launched under Beta tag in the UK. Microsoft at that time promised to remove the tag only under one condition i.e if its experience would be different from the competition and if the results would be outperforming in terms of UK relevancy.

The Bing team reached its objective on November 12, 2009 and the credit goes to London-based Search Technology Center. Microsoft says that 60 engineers behind the project in Soho have done extensive job at localizing the Bing global experience for the UK users in just 5 months.