Example of literature reviews

from Helen M. Paterson (2004), “Co-Witnesses and the Effects of Discussion on Eyewitness Memory.” PhD Thesis submitted to UNSW.

Review section description


Overview of the Thesis “Introduction”
Less than 2 pages long.
First paragraph:

  • Stated overall objective of thesis.

  • Defined introduced term.

  • Provided broad motivation for interest in the area.

  • Introduced the sections of the thesis which would address overall objective.

Next four paragraphs described the contents and purpose of each section of the thesis.

“Whereas the legal system assumes that the testimony given by eyewitnesses should be independent of one another (ref.), this is frequently not the case. … Because eyewitness information is often conveyed from one witness to another through discussion, it is important to ascertain the effects of co-witness information on the validity of eyewitness testimony. To address this aim, …”

Ch. 1. Literature Review of Relevant Research

The overall goals of this chapter were firstly to establish the significance of the general field of study, then identify a place where a new contribution could be made. The bulk of the chapter was on critically evaluating the different methodologies used in this field so as to identify the appropriate approach for investigating the research question(s).

1. Establishes research territory.

1. “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.”

2. Establishes significance of territory.

2. “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.).”

3. Establishes research niche. (Briefly reviews what has been found, and then identifies a gap. Discusses what has been found, but points out inconsistency of results.)

3. “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.”

4. Motivates next part of literature review.

4. “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.”

5. Further justifies the need to investigate the impact of social influences on memory.

5. “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.”

6. Reviews the chronological development of research in this area (an approach that is useful at times, but not always the best). Discusses one key paper at a time by describing its methods and key findings, but then identifies weaknesses in the method and/or limitations in the findings. Then discusses how the next researchers tried to address these problems.

6. “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.”

7. Repeats 6 for another sub-topic.

7. ...

8. Overall conclusion / summary which indicated why she was going to use a particular methodological approach to her research.

8. “… 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.”

Ch. 2. Theoretical Explanations of Memory Conformity

1. Establishes a reason for this chapter and states the purpose.

1. “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.”

2. Introduction/overview of the structure of the review.

2. “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.”

3. For each of the four explanations, followed typical structure of: (a) definition; (b) when might happen; (c) evidence supporting explanation; (d) limitations of this explanation as being “the whole story” (this is the “critical” part of a critical review).

3. “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)”

4. Thought went into the choice of order. There was some comparison between later and earlier explanations and the synthesised conclusions that can be drawn.

4. “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.”

5. Sums up what has been learned from the review of the four current theoretical explanations. Identifies which explanations are likely to be valid in explaining the results of experiments conducted for this thesis. Aims to resolve theoretical uncertainties.

5. “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)”

6. Discusses methodological issues in achieving aim.

6. “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.”

7. Introduces another question of interest and reviews what has been found so far.

7. “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.”

8. Relevance to thesis is made clear.

8. “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.”

Ch. 5. Study 3: Co-Witness Contamination

Chapter had structure:

  • Introduction

  • Methods

  • Results

  • Discussion

The Introduction introduced the particular study to be reported on, and also contained a three and a half page literature review which:

  • Linked back to the relevant to the general findings of the earlier literature review chapters.

  • Briefly reviewed the broad motivation for this study and identified that two previously used methodologies in this field would be compared in order to resolve questions about the findings of previous studies which had only used a single methodology.

  • Previous literature was used to generate specific hypotheses to test.

  • Additional literature was reviewed so as to provide a justification for a second objective to be investigated in the study reported on in this chapter.