Last week we looked at the use of Boolean op­er­a­tors for search­ing on the In­ter­net and in EB­SCO, which you should be us­ing in the Na­tion­al Li­brary when you're work­ing on SBA's. Be­low, you'll find a re­view of the log­i­cal op­er­a­tors. We will in­tro­duce po­si­tion­al op­er­a­tors and trun­ca­tion. Boolean op­er­a­tors help you to zoom in on the sites you need for re­search.

The Log­i­cal Op­er­a­tors:

Here are the most com­mon op­er­a­tors for a Boolean search.

AND - Each recordy­ou pull up must con­tain all search terms that you type. This means that (AND tends to nar­row a search).If you type in French dessert cook­books AND Ina Garten AND will look for all of those terms.

OR - Each record must con­tain at least one search term.If you type in French dessert cook­books OR Ina Garten, you get one of the oth­er.(In oth­er words OR tends to broad­en a search).

A third log­i­cal op­er­a­tor is the NOT op­er­a­tor. This is not high­ly rec­om­mend­ed in high school be­cause it is dif­fi­cult to nav­i­gate your way through such search­es.Some­times it is help­ful.The NOT op­er­a­tor elim­i­nates pos­si­bil­i­ties, but it can some­times elim­i­nate in­for­ma­tion you want or need.For in­stance, I might want to do a re­search pa­per on Dis­eases of the co­coa plant, but I don't want Witch's Broom,I could do a search like this: Co­coa AND dis­ease NOT Witch's Broom.That search would elim­i­nate witch's broom, but there might be some use­ful in­for­ma­tion about co­coa dis­eases in those ar­ti­cles about Witch's Broom.

You can al­so see how use­ful a Boolean search is, in this case, if you con­sid­er you might be do­ing a re­search pa­per on Co­coa re­search, but you don't know if it's spelled Witch's broom OR Witch­es broom. You could take care of that by search­ing for both terms, get­ting the cor­rect spelling and then nar­row­ing your term.

The Po­si­tion­al Op­er­a­tors:

Boolean po­si­tion­al op­er­a­tors al­low you to re­trieve on­ly those records that ap­pear in the or­der you put them.This helps to nar­row a search as well.Here are two use­ful po­si­tion­al op­er­a­tors to use:

Adj – Here, search terms must be ad­ja­cent (side by side), in the same or­der.This would help for search­ing Witch's broom so that you don't pick up In­ter­net ar­ti­cles that con­tain the term Witch's or broom.

Same - Here, you search for terms that might not be in the same or­der.This is par­tic­u­lar­ly help­ful if you're search­ing for a gen­er­al term that could be ex­pressed in many dif­fer­ent ways.

Ex­am­ples of Search Ex­pres­sions Us­ing Po­si­tion­al Op­er­a­tors:

drug SAME abuse <<Re­trieves drug abuse, abuse of drugs, abus­ing drugs, abused drugs

Witch's ADJ broom <<Re­trieves Witch's broom on­ly

TRUN­CA­TION - Ab­bre­vi­a­tions for a Boolean search

Once you know what sym­bols can be used for trun­ca­tion, you can re­trieve in­for­ma­tion in which you don't nec­es­sar­i­ly know the ex­act word or spelling. Trun­ca­tion al­lows you to pull up all the let­ters be­fore the sign which could bea ques­tion mark.

Ex­am­ples of Search Ex­pres­sions Us­ing Trun­ca­tion

co­lo? <<Re­trieves col­or, colours, Col­orado, colony, etc.

NEST­ING

Math ma­jors will love nest­ing.This al­lows you to build com­plex search­es.You build re­la­tion­ships for nest­ing by us­ing brack­ets just as you do in al­ge­bra.

Ex­am­ples of Search

Ex­pres­sions Us­ing Log­i­cal Op­er­a­tors

(moth­ers OR par­ents ) AND­dis­ci­pline

(air­port? OR air­plane?) AND ter­ror?

The first ex­am­ple will re­trieve records in which the words moth­er­sAND par­entsand dis­ci­pline ap­pear.

The sec­ond ex­am­pleis an even­broad­er search. Here, the ques­tion mark will al­low youtore­trieve air­port, air­ports, air­plane, air­planes in records where the term(s) ter­ror, ter­ror­ist, ter­ror­ize, ter­ror­ists, or ter­ror­ism ap­pear in the same record.