Computer Science Quiz 1-4: Key Terms & Definitions

What is information retrieval?

It's a field concerned with the structure, analysis, organization, storage, searching, and retrieval of information

Which of the following are examples of work within the Information Retrieval field?

web search engines

filtering for documents of interest

the design of a relational database for a library

classifying books into categories

automatically answer customer support questions

web search engines,

filtering for documents of interest,

classifying books into categories,

automatically answer customer support questions

web search

gathering and finding information on the web

vertical search

gathering and finding information focused on a specific topic

desktop search

gathering and finding information on a single computer

peer-to-peer search

gathering and finding information on network of independent nodes

enterprise search

gathering and finding information within a company's network

Find out what is going on today at UCI?

relational database vs search engine

search engine

Find all female students whose last name is Smith

relational database vs search engine

relational database

Find how to split words in python

relational database vs search engine

search engine

What is the weather like in bali

relational database vs search engine

search engine

What were the temperature and humidity values registered in Crystal Cove between 9/1/2019 and 10/1/2019?

relational database vs search engine

relational database

What contributes to the relevance of a document with respect to a query in the context of a search engine?

prior queries made by the same user, the author of the document, the geographic location of the person who's querying, the popularity of the document, textual similarity, the geographic origin of the document

True or False? The right side of the architecture pertains to processes that are done well before any query is done.

false

How is advertisement integrated with web search?

The user's query goes both to the search engine and the ad engine; the search engine retrieves the most relevant results, the ad engine uses an auction system on the query words.

Cost Per Mil (CPM)

Cost for showing the ad 1000 times

Cost Per Click (CPC)

Cost for users clicking on the ad after it is shown to them

The following is the syntax of a URL:

A://B/C?D#E

A: scheme

B: authority

C: path

D: query

E: fragment

Which of these are Universal Resource Identifiers (URI)?

ISBN 0-486-2777-3

rmi://filter.uci.edu

"Pride and Prejudice"

http://www.ics.uci.edu/~lopes

ISBN 0-486-2777-3

rmi://filter.uci.edu

http://www.ics.uci.edu/~lopes

Besides web crawling, what other ways are there to obtain data from Web sites?

targeted downloads of specific URLs

Downloads from the Library of Congress

Data dumps provided by companies and organizations

Web APIs provided by certain web sites

targeted downloads of specific URLs

Data dumps provided by companies and organizations

Web APIs provided by certain web sites

Consider the following robots.txt file:

User-agent: *

Disallow: /foo

Disallow: /bar

User-agent: Googlebot

Disallow: /baz/a

According to this, the Googlebot is

Allowed to crawl /foo and /bar

Not allowed to crawl neither /foo nor /bar

Not allowed to crawl /baz/a

Allowed to crawl /baz/a

Allowed to crawl /foo and /bar

Not allowed to crawl /baz/a

True or False?

"If something is on the Web, a Web crawler has the right to get it"

False

Hw1 (tokenization) pertains mostly to which of the following

index

text acquisition

text transformation

text transformation

How large is the web, measured in number of hosts?

O(quadrillion)

O(million)

O(billion)

O(trillion)

O(billion)

Consider the sequence of characters "hello!!"

is this a token

maybe, it depends on what your definition of a token is

Should crawlers wait between requests to the same web site?

yes

All the crawler traps that exist on the web are deliberately created

False

What is bad about crawler traps

they are hard to detect, they make web crawlers busy for no good reason, they prevent or delay crawlers from going to other sites

What is the frontier of a web crawler?

Its the set of URLs that have been seen but not yet crawled

What are HTTP status codes 2xx?

Page retrieved successfully

What are HTTP status codes 3xx?

Redirection

A normal crawler fetches pages directly from the web servers. However, your crawler used a cache server to fetch pages. Why?

Because having more than one hundred crawlers fetching pages directly could overload the ICS network if the crawlers are not properly developed

Which of the following methods can you DIRECTLY use to detect pages or documents that are near duplicates?

Simhash

Fingerprint

Cyclic redundancy check

document slope curve

Blake3

Simhash

Fingerprint

The deep web is a large part of the web that only has encrypted content, and thus it is not crawled nor indexed by normal search engines. T/F

False

Web crawlers can and should send hundreds of requests per second to a web site, because otherwise they will take a very long time to crawl. T/F

False

What is the main problem of using a term-document matrix for searching in large collections of documents?

It is an efficient use of memory

Should crawlers hit the same web site as fast as possible as a strategy to crawl faster?

No

What is an inverted index?

its a map with terms as keys and postings lists as values

what is the minimum information is a posting?

the document id

Consider the following sentences (each sentence is to be considered a different document):

S1: I tried searching for this error but got me nowhere.

S2: To be or not to be, this is the question.

S3: This seems to do the trick.

What are the postings for the term "to"?

S2, S3

Reading 1MB sequentially from memory is faster than Reading 1 MB sequentially from disk.

True

Reading 1 MB sequentially from memory is 2 times faster than Reading 1 MB sequentially from disk

False

In Boolean retrieval, a query that ANDs three terms results in having to intersect three lists of postings. Assume the three lists are of size n, m, q, respectively, each being very large

If you keep the lists unsorted, what best approximates the complexity of a 3-way intersection algorithm

O(nmq)