Literature review example analysis

This example shows how a literature review from a PhD thesis can be analysed for its structure, purpose and content.

Three sections of the thesis are analysed to show the:

relationship between the introduction and the literature review
structure and purpose of dedicated literature review chapters
inclusion of literature review in other chapters of the thesis.

Access the thesis

Co-witnesses and the effects of discussion on eyewitness memory by Helen M Paterson

Overview of thesis (introduction)

This introductory section is less than two pages long.

The first paragraph:

states the overall objective of the thesis
defines the introduced term
provides broad motivation for interest in the area
introduces the sections of the thesis that will address the overall objective.

The other paragraphs describe the content and purpose of each section of the thesis.

Literature review

The literature review is made of up of two chapters.

Chapter 1: Literature review of relevant research

The overall goals of this chapter are to firstly establish the significance of the general field of study, and then identify a place where a new contribution could be made.

The bulk of the chapter critically evaluates the methodologies used in this field to identify the appropriate approach for investigating the research questions.

Purpose	Example
Establish research territory	“Approximately 77,000 individuals are arrested in the United States each year based primarily on eyewitness testimony (ref.). … Given the pivotal role that eyewitness testimony plays in some trials, it is important to establish whether or not the jury’s faith in this testimony is warranted.”
Establish significance of research territory	“One study has shown that eyewitness errors are the most common cause of false convictions (ref.). Almost all innocent individuals exonerated by DNA evidence had been convicted primarily as a result of erroneous eyewitness evidence (ref.) Consequently, a great deal of research has focussed on the unreliability of eyewitness testimony (refs.).”
Establish research niche – discusses what has been found then identifies a gap and points out the inconsistency of results	“The current thesis examines the third way that postevent misinformation may be encountered: through other witnesses. This area has been surprisingly neglected until recently, as the majority of the literature on eyewitness testimony has focussed on the effect of questions and media reports containing misleading information.”
Motivate the next part of literature review	“Yarmey and Morris (1998) suggest that, ‘The capricious results among these investigations are probably due to methodological differences and variability in subject matter’ (p. 1638). To appreciate the effects of co-witness information on eyewitness reports, we must examine, in detail, the different methodologies that have been used to investigate this topic.”
Further justify the need to investigate the impact of social influences on memory	“Traditionally, researchers in memory have aimed to keep procedures free from contamination, such as other people’s memories (ref.). However, such a narrow focus may not fully explain how people remember (ref.). Because such ‘contamination’ is common to memory, understanding its effects enables greater knowledge of memory itself (ref.). … Therefore, instead of intentionally avoiding the social aspects of memory, they should be explored in their own right.”
Review the chronological development of research in this area (a chronological approach may not always be appropriate) Discuss one key paper at a time and for each paper: describe methods and key findings identify weaknesses in the method or limitations in the findings discuss how the next researchers tried to address these problems.	“While the above studies provide valuable information regarding the social aspects of memory, caution needs to be exercised before applying these results to the judicial area. One should not assume the results obtained from studies using stories and word lists as stimuli can be generalised to forensic contexts.” … “That is, the differences found between individuals and groups could simply be due to the participants giving their reports for a second time …” … “A limitation of this research on collaborative memory is that the memory of groups is compared with that of individuals. … group performance should not be compared with individual performance but rather with ‘nominal groups’ comprised of pooled, non-redundant data from the same number of people tested individually.”
Overall conclusion or summary that states why a particular methodological approach has been chosen	“… Most research involving the Experimentally Induced Information methodology seeks to identify the influence of misinformation presented by one witness to another, and therefore the assumption is made that discussion between witnesses is a detrimental process. It may therefore be advantageous to also investigate the effects of co-witness information using Natural Discussion Groups as this methodology has high ecological validity. However, few studies have used this methodology, and those that have, have yielded mixed findings. Therefore, future investigation using the Natural Discussion Group methodology would be helpful to better understand the effects of discussion on memory.”

Chapter 2: Theoretical explanations of memory conformity

Purpose	Example
Establish a reason for this chapter and state the purpose	“While the misinformation effect is a well-established phenomenon, ‘what remains in dispute is the nature of a satisfactory theoretical explanation’ (ref.). … Therefore, in order to understand why memory conformity occurs, we must draw from both cognitive research on memory and social research on conformity. In this section, relevant cognitive and social theories are discussed in order to (1) explain the occurrence of memory conformity and (2) describe factors that influence memory conformity.”
Introduction/overview of the structure of the review	“Four distinct explanations have been offered for the memory conformity effect: (1) … The empirical evidence relevant to each of these explanations is reviewed in this section.”
Discuss each of the four explanations using the following structure: definition when it might happen supporting evidence limitations of the explanation (this is the 'critical' part of a critical review).	“Whilst normative social influence may explain the conformity that occurs in …, it is an unlikely explanation for memory conformity that may occur when people give individual statements following discussion in the absence of their co-witness. (Then reason why)”
Compare explanations and draw synthesised conclusions	“The suggestion that memory conformity is a result of biased guessing is similar to the informational influence explanation because in both instances … However, the distinguishing feature between the two explanations is that …” … “Whilst biased guessing may account for the misinformation effect that occurs in some instances (refs.), research suggests that it is not the only reason for the occurrence of the misinformation effect. (Supporting evidence) … This suggests that the misinformation effect may be due at least partially to memory impairment, rather than just biased guessing.”
Summarise what has been learned from the review of the four current theoretical explanations Identify which explanations are likely to be valid in explaining the results of experiments conducted for this thesis Aim to resolve theoretical uncertainties	“Informational influence, biased guessing, and modification of memory may help to explain why memory conformity occurs when participants are tested individually, as they are in the studies presented in this thesis. … The research presented in this thesis compares these alternative explanations to determine which best explains memory conformity in individual recall following co-witness discussion. (Why this is important to do)”
Discuss methodological issues in achieving aim	“One way to determine whether memory conformity occurs because of biased guessing is to …” “Experiments described in this thesis (Studies 5-7) include a warning for some participants about possible misinformation in an attempt to determine whether participants report misinformation because of informational influence or memory change.”
Introduce another question of interest and review what has been found so far	“Whist it has been shown that in some circumstances many people tend to conform to the opinions of others, we also know that some people are able to resist conforming in some situations. For example, … This section of the literature review examines factors influencing whether or not a person is likely to conform that are (1) in the situation, and (2) within the individual.”
Clarify the relevance to the thesis	“Although the experiments described in this thesis do not attempt to manipulate and test the factors that influence conformity, they are used to help understand the results obtained and consider implications of the findings.”

Chapter 5, Study 3: Co-Witness Contamination

This chapter has the following structure:

Introduction
Methods
Results
Discussion.

The introduction introduces the particular study to be reported on, and includes a three-and-a-half page literature review.

The literature review in this chapter:

links back to the relevant general findings of the earlier literature review chapters
briefly reviews the broad motivation for this study
identifies that two previously used methodologies in this field will be compared to resolve questions about the findings of previous studies which had only used a single methodology
uses previous literature to generate specific hypotheses to test
reviews additional literature to provide a justification for a second objective to be investigated in the study reported on in this chapter.