0625 booleans4

Coming attractions : 

Coming attractions Stephen Glass reading for tomorrow Wednesday we meet in Alden 251 (computer room off Learning Commons)

Booleans : 

Booleans

Boolean Logic : 

Boolean Logic A system of logic Named for George Boole 1815-1864 He wanted to figure out how the relationship between ideas and concepts could be described mathematically, but in plain English. Boolean logic is widely used in mathematics, philosophy, programming The foundation of computer arithmetic

Boolean Logic : 

Boolean Logic Boolean logic deals with sets A set is a group of items. A set is generally only a portion of the universe of all possible items. Examples: The set of students in info-gathering is a portion (or a subset) of all students. The set of web pages about dogs is a portion (or subset) of all web pages.

Thinking about sets : 

Thinking about sets For our purposes, sets will be groups of records/”hits” that come back as we research topics. Boolean logic will help us get a set of hits that is the right size – not so big that you can’t read it all (1,744 articles) or so small that you miss what you want (3).

Lets take a step back : 

Lets take a step back We already know how to broaden and narrow the set of results using the word tree Keyword “animal” – 215929 hits Keyword “dog” – 29561 hits Keyword “dachshund” 130 hits (still too many, but much better)

In human logic … : 

In human logic … Dachshund is a subset of dog. Dog is a subset of animal. Dachshund Dog animal

But to computers… : 

But to computers… Human logic only sort-of works – Computers don’t understand concepts, they just read words. Some of those sites about dogs will really be about hot dogs. A search for dachshunds won’t find an article which calls them only “wiener dogs.” None of these sets would find articles which only use the term “canine.”

Operators : 

Operators Boolean Logic uses operators as mathematical commands to broaden and narrow sets. Operators you will have to know AND OR NOT ADJ Near Truncation symbol (*)

AND : 

AND How are dogs used to keep the elderly company? dog AND elderly (results include only the overlap area)

elephant AND eggs : 

elephant AND eggs finds ALL terms “Why would an elephant destroy bird eggs?” “Eggs used for softening elephant skin.” does not find “Egg-based solution as dermatological treatment for minor abrasions on elephant hide.” AND

OR : 

OR How are dogs used to keep the elderly company? dog OR elderly (results include all parts of both sets)

Best if you make groups of similar terms : 

Daschs-hound OR wiener OR dog denim OR cotton OR fabric jeans OR pants OR clothing OR Best if you make groups of similar terms

For example : 

For example correct: (cocoa OR chocolate) AND cake incorrect (cocoa OR cake) AND chocolate OR

AND NOT : 

AND NOT dog AND NOT elderly (the red circle without the overlap)

Truncation symbol : 

Truncation symbol bird* means bird, birds but also birding, birder… Other symbols: # $ ? Some resources have an automatic search for the S form of words without a symbol. (In these “egg-based” would have been a hit.) Some resources have wildcard – a symbol that can stand in for anything (just like poker) *

Slide 17: 

Wiener ADJ Dog = “wiener dog” Wiener ADJ4 Dog = will find “wiener and other dogs” ADJ

probe ADJ droid : 

probe ADJ droid finds “CG probe droid in Star Wars I tricky to light.” “Scientists probe droid progress at AI conference.” does not find “Scientists probe progress in droid research at AI conference.” “Could a droid probe mine fields in Iraq?”

But… : 

But… probe ADJ4 droid does find “Scientists probe progress in droid research at AI conference.” but not “Could a droid probe mine fields in Iraq?’ (With ADJ, order is important) ADJ

probe NEAR droid : 

probe NEAR droid finds the hits the ADJ search missed “Scientists probe progress in droid research at AI conference.” “Could a droid probe mine fields in Iraq?” plus “A droid that can probe mine fields developed by bicycle firm.” NEAR

Slide 21: 

Writing SYNTAX is putting sets with operators to create queries) two sets: chocolate AND cake two sets: chocolate AND (cake OR cookies) three sets: chocolate AND cake AND NOT recipes SYNTAX

How parenthesis matter : 

How parenthesis matter Censor* and (drugs or narcotics) Finds: Censorship of drug language Narcotics ads censored Court upholds narcotics censorship Censor* and drugs or narcotics Finds: All these, plus any page with the word “narcotics”

Drugs AND censorship AND NOT advertisement* : 

NOT Drugs AND censorship AND NOT advertisement* wiener AND dog AND NOT (hot ADJ dog)

Sets inside of sets : 

Sets inside of sets ((elephants OR mammals) AND symbiosis) AND (birds OR insects) --two sets (elephants OR rhinoceros) AND symbiosis AND ((bird OR birds) OR (egg OR eggs)) --three sets (((Africa* NEAR elephant) OR (black OR white) rhinoceros)) AND symbiosis) AND research --two sets (simple is best – most engines can’t handle the complex stuff.) Nests

Taking it to the street : 

Taking it to the street Academic Search Complete select field (when would different fields be effective?) sort results (why?) narrow results by subject select database