1 Kuliah 4 : Informed Search. 2 Outline Best-First Search Greedy Search A* Search.
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Transcript of Search
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Search
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Contents
• Introduction to Search• Google Account/Gmail• Results page• The Google search algorithm• Preferences• Forming a query• Operators• Other Google search applications• Other Google applications
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Introduction
• What search engine(s) do you use?• What searches have you done lately?• Google is not necessarily the best search engine
– http://www.nytimes.com/2009/07/09/technology/personaltech/09pogue.html
• However, if you can use Google well, you will know what to look for in other engines
• For the rest of this lecture, let's get to know Google well, both its search and related capabilities.
• From now on these lecture notes will disappear from the screen….
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Google Account/Gmail
• A few Google facilities are available only to those with a Google account or gmail.– Blogger, YouTube comments, Google Groups, Web History,
Google Docs
• You can sign up for these facilities at www.google.com/accounts/login.– You can have an account without having gmail, using another
email address.
• Pros of Gmail– Available through any browser, 1GB storage, groups mails by
subject, excellent search, good spam filter, nice add-ins.
• Cons of Gmail– Lots of ads, possible privacy problems, no self-delivery,
conversations cannot be split up.
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The Results PageSponsored (PPC) Links
Results
Search Toolbar
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How are Google’s search results ordered?
• Many (200+) factors considered by Google’s Algorithm• This algorithm is very important to businesses
– Every business wants its page at the top!– Entire books, courses devoted to Search Engine Optimizaton:
The art/science of getting your website at the top of results
• Algorithm is tweaked by Google daily• Most important factor in algorithm: Page Rank
– Page Rank is named after Larry Page, one of its inventors. Larry and Sergey Brin founded Google.
• Google blew away the competition because it had Page Rank; no other search engine did.
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What is Page Rank?*
• Very roughly, the page rank of a page is the number of pages that link to that page
– See those pages with the operator link:• http://www.google.com/intl/en/help/operators.html#link
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What else is in Google's Algorithm?
• Google will rank "your" page high in the results of a search for some keywords if:– The keywords are in prominent places on your page
• Prominent = page title, headings, meta tags, text
• Meta tags are part of the HTML of a page, not viewable by a user
– The pages, pointing to your page, have many links pointing to them, i.e. have high page rank.
• This is part of the definition of Page Rank
– The keywords are close together on your page– The keywords are in the anchors of the pages pointing to your
page
• Now we'll move on to learning how to use Google search
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Search History
• Each browser keeps a history of the pages you have searched in that browser, on that computer.– Helpful to autocomplete when you type– This has nothing to do with google.
• You can disable or clear that history feature.• Firefox:
– Clear: Tools/Clear recent history• Click details and clear only the browsing and download history
– Disable: Tools/Options/Privacy/Clear history when Firefox closes
• Other browsers: http://www.google.com/support/websearch/bin/answer.py?answer=465
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Web History
• This is a history of your google searches.• You can turn it on when you register your Google
account, and access it at www.google.com/history • You can search it, remove items from it, see trends in
your google search history
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Preferences• On Google's home page, at the upper right corner, click
settings/search settings• Note languages, number of results• Query suggestions
– Uses advertisements as well as your web history
• SearchWiki: Customize your searches!
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Forming a Query• What you don’t want: Use the minus sign, -
– Ari Shapiro –NPR– Omits all the Ari Shapiros not at NPR
• A phrase: Use quotes “…”– “Dan Shapiro” – omits all the "Dans" and the "Shapiros"
• Something you must include: Use a plus +– Len Shapiro +”Portland State University”– Shows only the Len Shapiros at PSU
• Show only certain filetypes: filetype:– Google filetype:ppt
• Look within a certain domain: site:– Cyberculture site:www.pdx.edu
• Do this and more on the Advanced Search page– www.google.com/advanced_search
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Operators on Keyword(s)
• Don't put a space after the colon!• Intitle:"tree removal"
– Displays only sites whose titles include the phrase "tree removal"
• Define:personable– Gives definitions from the web
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Operators on URLs
• Don't put a space after the colon!• Cache:www.cs.pdx.edu/~len
– To see an old copy of my web page
• Related:www.portlandfoodanddrink.com– To find similar pages
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Miscellaneous Operators
• Phonebook:Leonard Shapiro Portland Oregon• Movie:97223• Weather:portland,oregon• Special number searches
– UPS, FedEx, USPS, VIN, ISBN
• www.google.com/intl/en/help/features.html
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Which Principles does Google embody?
• Data Rules: The value of an application is increased by the scale and dynamism of the data it manages
• The long tail: Small products/ideas make up the great majority of all products/ideas.
• Use your Users: Enable users to contribute content to the application
• The Power of Groups: Apply the wisdom of users to solve problems
• Enable Community: Enable users to share their experiences in your application
• Folksonomy, not Taxonomy: Utilize user-generated tags to classify items, instead of expertly generated categories
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Other Google Search Applications
• Important: Use your search skills• Images
– Tiger -white
• Videos: youtube and more!• News (location: , source: )• Shopping• Groups (author: group: insubject: )• Scholar• Finance• Blogs
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Other Google Applications• Maps, www.maps.google.com
– Similar to mapquest or maps.yahoo.com, but has satellite/terrain views
• Earth– Must download as a separate application– As if you could fly anywhere and see below you
• Documents & Spreadsheets– Similar to Microsoft Word & Excel– Not quite compatible
• E.g., if you load a Word document into G, it may not display completely• Google Docs was meant to be a new word processor, not a copy of Word
– http://tinyurl.com/2k32sh
– Documents stored on the Web– Easy to share with others– Price is right
• Gmail– We've seen this before
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More Google Applications• Calendar
– Stored on the web– Easy to share with others
• Google Alerts (under even more)– Be informed (email) when anything (keyword based) happens
• Picasa: Photo editing, sharing• Directory: directory.google.com
– Another way to search the web– Oldie but goodie
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Other search engines
• Wolfram alpha: www.wolframalpha.com – Computational knowledge engine– Try ../examples
• A recent article ranking customer satisfaction with search engines: http://tinyurl.com/lvnca2