02. literature reviews

8/9/2019 02. Literature Reviews

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CS Research MethodsCS Research MethodsDr. Tamara Cher R. Mercado

Literature Searches and

Information Gathering(Literature Review)


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IntroductionIntroduction

The "literature" of a literature review refers

to any collection of materials on a topic,

not necessarily the Great Literary Texts

of the World.

y A review does not necessarily mean

that your reader wants you to give your

personal opinion on whether or not youliked these sources.


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What is a literature review?What is a literature review?

y A literature review discusses publishedinformation in a particular subject area, andsometimes information in a particularsubject area within a certain time period.

y A literature review can be just a simplesummary of the sources, but it usually has anorganizational pattern and combines bothsummary and synthesis.

A summary is a recap of the importantinformation of the source

A synthesis is a re-organization, or a reshuffling,of that information.


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What is a literature review?What is a literature review?

y A literature review may:

give a new interpretation of old material or

combine new with old interpretations;

trace the intellectual progression of the field,including major debates;

evaluate the sources and advise the reader on

the most pertinent or relevant.


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Why do we write literatureWhy do we write literature

reviews?reviews?y Provide handy guide to a particular topic.

y Gives an overview or act as a stepping

stone.

y Keeps professionals up to date with what

is current in the field.

y Provide a solid background for a research

paper's investigation.


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PreliminariesPreliminaries

y Find models

y Narrow your topic

y

Consider whether your sources arecurrent


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Strategies for Writing theStrategies for Writing the

Literature Review:Literature Review:1. Find a focus A literature review, like a term paper, is usually

organized around ideas.

Consider what themes or issues connect yoursources together.

x Do they present one or different solutions?

x Is there an aspect of the field that is missing?

x How well do they present the material and do they

portray it according to an appropriate theory?

x Do they reveal a trend in the field? A raging debate?


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Literature Review:Literature Review:2. Construct a working research statement statement will not necessarily argue for a

position or an opinion; rather it will argue for

a particular perspective on the material. Example:

x The current trend in treatment for congestive heart

failure combines surgery and medicine.

x More and more cultural studies scholars are accepting

popular media as a subject worthy of academic

consideration.


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Literature Review:Literature Review:3. Consider organization Basic Categories

x Introduction: Gives a quick idea of the topic of the

literature review, such as the central theme ororganizational pattern.

x Body: Contains your discussion of sources and is

organized either chronologically, thematically, or

methodologically.x Summary/Conclusions/Recommendations: Discuss

what you have drawn from reviewing literature so

far. Where might the discussion proceed?

x Synthesis, Theoretical Framework, Conceptual Framework


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Organizing the BodyOrganizing the Body

y Chronological:

By publication

By Trend

y Thematic: organized around a topic or issue, rather than

the progression of time.

yMethodological:

Does not have to do with the content of thematerial but focuses on the "methods" of theresearcher or writer.


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Additional SectionsAdditional Sections

y Current Situation

y History

yMethods and/or Standards

y Questions for Further Research


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Guidelines in Writing the LiteratureGuidelines in Writing the Literature

ReviewReviewy Use evidence Your interpretation of the available sources must be

backed up with evidence to show that what you aresaying is valid.

y

Be selective Select only the most important points in each source

to highlight in the review.

y Use quotes sparingly

y Summarize and synthesizey Keep your own voicey Use caution when paraphrasing

y Revise, revise, revise


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Citing: Rules of thumb (Citing: Rules of thumb (ZobelZobel 2004)2004)

y If you discuss a paper in detail or note some particularcontribution it makes, it must be cited.

y Claims, statements of fact, discussions of previous workshould be supported by references, if not supported by yourcurrent work.

Do not cite to support common knowledge; Do not end every sentence with a reference

y References to your own previous work is allowed if it isrelevant to your current work but gratuitous self-referenceis counterproductive

y Attribute work correctly, in particular, when relying onsecondary sources Bad: According to Dawson (1981), stable graphs have been

shown to be closed

Good: According to Kelly (1959; as quoted by Dawson,1981),stable graphs are closed


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Citing (1)Citing (1)

KNOWITALL is an autonomous

system that extracts facts, concepts,

and relationships from the web.

KNOWITALL is seeded with an

extensible ontology and a smallnumber of generic rule templates

from which it creates textextraction rules for each class and

relation in its ontology. The system

relies on a domain- and language-

independent architecture topopulate the ontology with specific

facts and relations.

An example of the described system is

KNOWITALL [19]. It is an autonomous

system that extracts facts, concepts, and

relationships from the web.KNOWITALL [19] is seeded

with an extensible ontology and a small

number of generic rule templates from

which it creates text extraction rules

for each class and relation in itsontology. The system relies on a

domain- and language independentarchitecture to populate the ontology

with specific facts and relations.

References are not meant to indicate copying! This is wrong!


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KNOWITALL is an autonomous

system that extracts facts, concepts,

and relationships from the web.

KNOWITALL is seeded with an

extensible ontology and a smallnumber of generic rule templates

from which it creates textextraction rules for each class and

relation in its ontology. The system

relies on a domain- and language-

independent architecture topopulate the ontology with specific

facts and relations.

An example of the described system

is KNOWITALL [19]. Given an initial

ontology and a small number of rule

templates which do not depend on theclass and relationships in the ontology,

KNOWITALL generates text

extraction rules for each class and

relationship in the ontology. These text

extraction rules are then applied totexts found on the web. Rule

applications populate the ontology withinstances of the concepts and

relationships in the ontology.


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y A reference in ordinal-number style never starts asentence Wrong: [9] Disaster rescue is a serious social issue.

Correct: Disaster rescue is a serious social issue [9].

y

An ordinal-number style list of references is acomma-separated list of numbers enclosed in onepair of square brackets Wrong: The humanoid soccer robots are fully autonomous

[5][9].

Correct: The humanoid soccer robots are fully

autonomous [5,9].y A reference never occurs in a section heading

Wrong: Section 5. The History of RoboCup [9]

Wrong: Section 5. The History of RoboCup (Henry 2006)


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y A reference never comes after a full stop Wrong: 2-on-2 teams of autonomous mobile robots play

games in a rectangular field color-coded in shades of grey.[9]

Correct: 2-on-2 teams of autonomous mobile robots play

games in a rectangular field colour-coded in shades of gray[9].

y Beware of the differences between ordinal-numberstyle and author-date style Wrong: [11,12] stresses the importance of algorithmic

support for formal methods. Correct: Wolper (1996a, 1996b) stresses the importance

of algorithmic support for formal methods.

Correct: Wolper [11,12] stresses the importance ofalgorithmic support for formal methods.


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y Examples of correct use of author-date style: While Wolper (1996a) does not argue that

compositionality in proof systems for concurrency isundesirable, he claims that achieving it without algorithmicsupport is mostly useless.

Recent work (Wolper 1996a, 1996b) stresses theimportance of algorithmic support for formal methods.

Wolper (1996a, 1996b) stresses the importance ofalgorithmic support for formal methods.

The completion procedure may fail in general, but hasbeen extended to a refutationally complete theoremprover (cf. Lankford 1975, Hsiang and Rusinowitch 1987).

Completion procedures for conditional equations havebeen described by Kounalis and Rusinowitch (1988), andby Ganzinger (1987a, 1987b).


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QuotingQuoting

y Direct quotation from Koza [1992]; clearly indicated assuch; restricted to (less than) one paragraph; sourcestated.

Such dangers are catered for by ensuring the closure of the function set.Koza [1992] states that:

The closure property requires that each of the functions

in the function set be able to accept, as its arguments,

any value and data type that may possibly be assumed by

any terminal set. That is, each function in the functionset should be well defined and closed for any combination

of arguments that it may encounter.

Without closure, many individuals could have their fitness drasticallylowered as a result of minor syntactic errors.


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QuotingQuoting

y Quotation clearly indicated by quotation marks; alterationsindicated in square brackets; source stated.

Bickle [1996] states that [t]he superior method to obtain compactand accurate solutions is the method of adaptive parsimony

pressure [. .. ].

yQuotation clearly indicated by quotation marks; alterationsindicated in square brackets; source stated.

Day [2005] reports that GP shows great promise in creating robustclassifiers for [Automatic Speaker Verification] purposes whereprograms attempt to recognise the voice of a known individual.


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QuotingQuoting

y Direct quotation indicated by quotation marks andindentation; source stated.

More recently, in 1999, Tim Berners-Lee [3], father of the World

Wide Web (WWW) speaking of the WWW stated that he saw it as

an information space through which people cancommunicate; but communicate in a special way:

communicate by sharing their knowledge in a pool. The

idea was not that it should be a big browsing medium.

The idea was that everybody would be putting their ideas

in as well as taking them out.

A Wiki is in WardCunninghams [43] original description:

The simplest online database that could possibly work.


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QuotingQuoting

y Avoid excessive quotation.

y Quotation is only appropriate

where you want to comment on the

statements made by someone else

where the quote is of some historical

significance

y In all other cases, use your own words


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Evidence and SupportEvidence and Support

Intelligent agents, autonomous or semi-autonomous systems thattake decisions and perform tasks in complex, dynamicallychanging environments, revolutionized the field of AI.

y This is stating an opinion not a generally known and accepted fact

y As such it needs support which it currently lacksy Support could be provided by some statistical evidence or by a

reference

y (Made-up) example of statistical evidence:

The concept of intelligent agents was first introduced in 1983. By

2003, more than half of all papers published in the main forums of

AI, referred to the concept or made use of intelligent agents, and it

has spawned a world wide industry worth 5 billion US$ [2].

where [2] is a reference to the source of these statistics.


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To deal with information in the web environment what is needed is

a logic that supports modes of reasoning which are approximate

rather than exact.

y Again, this is stating an opinion not a generally known and

accepted fact

y Support could be provided by an argument or by a reference

A reference could point to a scientific paper where this opinion is

stated and argued for

An argument could be an example illustrating the advantage ofapproximate over exact reasoning

y If that example is taken from a source, then again that source

needs to referenced


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To deal with information in the web environment what is needed is a logic

that supports modes of reasoning which are approximate rather than

exact.

Better formulation:It has been argued by Oberschlau [1] that to deal with information

in the web environment what is needed is a logic that supports

modes of reasoning which are approximate rather than exact.

or

According to Oberschlau [1], to deal with information in the web

environment what is needed is a logic that supports modes of

reasoning which are approximate rather than exact.


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Therefore, once our system is enhanced with our common knowledge

about things we know, [it] could be seen as an intelligent entity. A

brilliant example is the Cyc knowledge base.

y The phrase brilliant example is ambiguous:

Cyc a system incorporating common knowledge and it is a good

example of such a system

versus

Cyc is a brilliant system incorporating common knowledge

y Both readings require support, in particular, the second version


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The author agrees with Lenat (1995)

As Lenat (1995) has noted in an earlier paper, Cyc is a brilliantsystem.

Lenat (1995) demonstrates that Cyc is a brilliant system.

Cyc is a brilliant system (Lenat 1995).

The author disagrees with Lenat (1995)

Lenat (1995) alleges that Cyc is a brilliant system.

Lenat (1995) claims that Cyc is a brilliant system.

The author is neutral with regard to the truth of the statementCyc is a brilliant system

Lenat (1995) states that Cyc is a brilliant system.


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The most popular ways to compress data are the Huffman coding and

Shannon-Fano coding.

y It is unclear on what basis compression methods are judged to be

popular number of compressed files

number of users of compression software

number of developers of compression software

y In each case, statistical evidence seems to be required, e.g.

In 2004,60% of all compressed files were compressed using theHuffman coding or Shannon-Fano coding [3].

where [3] is reference to the source of these statistics.


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Some Free ResourcesSome Free Resources

y Citeseer. Digital library of750k freely available papers in

computer and information science

http://citeseer.ist.psu.edu

y Google Scholar. Searches scholarly literature on the web.

http://scholar.google.com

y Scirus. Searches journals (ScienceDirect) and web resources

http://www.scirus.com/

y Windows Live Search Academic. Search academic journals

and content for article titles, author names, article abstracts,and conference proceedings.

http://academic.live.com/


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Assignment #2 (minor)Assignment #2 (minor)

y Now that you have a research topic, look for

related studies conducted (at least 5).

y Read and review the literatures:

List titles of paper, author(s), date of publication, shortdescription

List quotations from each literature that you find

relevant to your study and explain why it is relevant.

Determine how the literatures can be organized inthe literature review document (Chronological,

Thematic, Methodological)

02. literature reviews

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