Literature review process
Before commencing a research project in earnest, it is necessary to select an interesting, important and feasible research problem. The student should then review the available academic literature and possibly other literature relating to the research problem. The purposes of undertaking a review of literature are to identify a research problem, develop hypoth- eses and develop methods (Thomas et al. 2005: 29–31). The research problem may have been identifi ed through other means, for example personal interest, media interest or career aspirations. Gratton and Jones (2004: 51–2) described some additional purposes of undertaking a lit- erature review, which include demonstrating knowledge of the research area, understanding of relevant theoretical concepts and determining the extent of previous research. Gratton and Jones also listed the identifi ca- tion of variables, which would be included in the process of formulating hypotheses identifi ed by Thomas et al. (2005: 55–7), and that the previ- ous fi ndings surveyed by the student could be compared with the stu- dent’s eventual fi ndings. The purposes of undertaking a literature review in sports science research in general also apply to the discipline of per- formance analysis. While performance analysis is an emerging discipline and theoretical concepts of sports performance may not have been fully developed, there are still relevant theoretical concepts from other disci- plines that performance analysis overlaps with, which should be covered by the student.
Thomas et al. (2005: 32–49) described the literature review as a process consisting of the following six stages that lead to the eventual end product of a written review of literature:
1. writing the problem statement;
2. consulting secondary sources;
3. determining descriptors;
4. selecting preliminary sources;
5. reading and recording the literature;
6. writing the literature review.
Getting organised
Students should be properly prepared to review previous literature in a manner that is reasonably systematic, while allowing the necessary fl exibil- ity to follow areas of previous research that they discover to be relevant which they had not anticipated. The student needs to record details of arti- cles that are read so that they can be used within the eventual review of literature chapter. Having a notebook dedicated to the literature search is a good idea and the students should bring this with them every time they go to the library. This avoids situations where the student fi nds relevant material but has to make a repeat visit to the library to record it or, worse still, forgets to record the paper or even where they found it. When the student has read a relevant paper, the title, author(s), journal/book details, publisher, volume, issue, page numbers and year/month should be recorded.
A summary of the research described in the paper should be written down, so that the student will understand what was done and what was found well enough to be able to explain this to others in their own words. The main evidence provided by a paper is the results, and critical consideration should be made of the methods used and any limitations of these. The introduction and discussion sections of papers should also be read as these draw the student’s attention to relevant theory and other evidence that may explain the results found. This information should be summarised by the student within their notebook and a list of key references used by the paper should also be recorded. This helps make the search for further research papers much more effi cient.
Research papers and other material that are read by the student will vary in their relevance to the student’s own study and so the volume and detail of what is recorded will also vary from paper to paper. There are some papers that will be so important that the student should photocopy them and keep within a dedicated folder of background material for their project. Other papers will be ones that the student will mention in their literature review but which may not be described as critically as others. As the student is conducting their literature search, they should periodically update an elec- tronic reference list they are maintaining. Writing references is much harder than writing natural text and it is not a task the student should be starting during the fi nal week of the project, so the earlier this is done the better.
Consulting literature
There is a wealth of sports science research in general and performance analysis research in particular that has been published in academic journals.
On entering the journal area of the library, it is apparent that there are thou- sands of papers within these journals. The student would, therefore, be unwise to sequentially search through contents pages of different journals for articles that may be relevant to their own research. The student should
instead use a systematic strategy for identifying relevant literature. The student should initially consult secondary sources such as research review articles and chapters of textbooks. Research reviews are not original research investigations but papers that survey the research done in a particular area.
There are journals such as Sports Medicine and Exercise and Sports Science Reviews that only publish research reviews. Other journals that usually publish original investigations may occasionally publish review articles.
An excellent example of a review paper in performance analysis of sport is a review of automated and semi-automated motion tracking systems used in elite soccer (Carling et al., 2008). This paper surveys the various com- mercial systems that are available as well as some other systems developed by academic institutions and used within time-motion analysis studies. The description of the underlying techniques used by these systems explores their strength and limitations with respect to the critical measurement issues of validity, objectivity and reliability. The paper also surveys motion analy- sis research that has been done using these techniques and the effi cacy of their use as indirect measures of physical demands and fatigue in soccer.
The authors also considered issues such as standardisation of variables used in such research and provided guidelines for the evaluation of the quality of measurements made by such systems. The paper refers to 92 sources, includ- ing previously published academic papers, papers that were ‘in press’ at the time of writing and websites containing information on commercial prod- ucts. There were 62 of these sources that were dated in the fi ve years between 2004 and 2008 when the review was published, making this paper an excel- lent secondary source for students studying movement in sport or the tech- niques involved in automatic player movement.
Textbooks are another type of secondary source and their advantage is that they are written by eminent people in the given fi eld who are in a posi- tion to discuss the state of the art in different areas covered within the chap- ters. A good example of a book chapter that is a secondary source that could be used by students in the early stages of their literature reviews is the book chapter on ‘Rule changes in sport and the role of notation’ by Williams (2008), which discusses the role of rules in sport, the various motivations for making rule changes as well as research into the effectiveness of rule changes that have been made. This chapter is not only a useful secondary source for students doing research projects on rule changes in sport, but is also a very good example of how to structure a review of previous research into logical subsections.
Other secondary sources include literature reviews within previous dis- sertations and encyclopaedias. Previous dissertations are done at a range of levels from undergraduate degree up to PhD and DSc. PhD theses will have undergone a thorough examination process and if any changes were neces- sary in the write up as a condition of a PhD award being made, then these changes will have been implemented. Some universities have similar regula- tions for Master’s level dissertations that will eventually be placed in the
library. However, undergraduate dissertations and many Master’s disserta- tions will not have undergone such a peer review process before being placed in the library. Therefore, students need to be aware that these literature reviews may not be examples of best practice. Students can pass their research project even if the literature review section receives less than 40 per cent of the marks allocated for that chapter. Students are encouraged to treat such dissertations as secondary sources that identify other material that they should fi nd and read. Literature reviews in previous dissertations may also give students ideas of how to structure their own literature review sections, but the fi nal decision should be based on a more logical considera- tion of the material reviewed and the different broad areas that have been covered. There are general encyclopaedias and specialised encyclopaedias as described by Thomas et al. (2005: 32). While there is no specialised encyclo- paedia in performance analysis of sport, there may be some useful defi ni- tions of terms that can be obtained from the sports science encyclopaedias identifi ed by Thomas et al. (2005).
The ultimate aim of consulting secondary sources is to identify primary sources of academic literature that the student can review. Primary sources are papers describing studies where data have been analysed and fi ndings presented. There are other means of identifying primary sources including internet searches, entering key words into electronic library catalogue searches, lists of abstracts or even just titles of papers presented at research conferences. Internet searches can identify primary sources published in reputable scientifi c research journals. However, internet searches can also lead to sites containing writings about a topic that have not been peer reviewed and may have been written by authors without any professional training or qualifi cation in the area. These internet sites may be about coach- ing, sport and sports performance but may have been established and main- tained by people purely as a hobby or personal interest. Students should not use material from such sites as primary sources of background material.
Other sites may be media sites containing useful quotes that the student may wish to use in initially setting the scene for their own research. The student should be aware that such material is often written in journalistic language that may not be scientifi c and often sensationalises issues. There are offi cial internet sites of scientifi c and professional organisations in sport and sports science. Material on these is useful, but the objectivity of such information should always be questioned, particularly when it comes from commercial organisations that are marketing their products and services.
The contents of research conferences can be identifi ed from conference programmes specifi ed on conference websites or in journals that occasion- ally devote an issue (or a supplement of an issue) to the abstracts from recent research conferences. For example, volume 25 number 3 of the Journal of Sports Sciences (February 2007) contains the abstracts of the annual BASES (British Association of Sport and Exercise Sciences) confer- ence that was held in Wolverhampton in September 2006. Performance
analysis abstracts can be found within the biomechanics and interdiscipli- nary sections of such an issue, with other abstracts related to performance analysis being included in the talent development, physiology and psychol- ogy sections. Research Quarterly for Exercise and Sport produces a supple- ment to its fi rst issue each year that contains the abstracts of the AAHPERD (American Alliance for Health, Physical Education, Recreation and Dance) annual convention and exposition. Volume 80 number 1 of this journal, published in March 2009, contained the abstracts of the AAHPERD national convention and exposition held in Tampa, Florida in 2008.
Primary sources are identifi ed by secondary sources, internet searches and other means and can be reviewed by the students. These primary sources are original research contributions that describe particular investigations that have been done where conclusions are drawn based on analysis of data.
These primary sources refer to previous research when establishing a ration- ale for the study described. Sometimes, when describing the general back- ground to a study, a primary source may even refer to a secondary source that the student had not previously been aware of. The process of reading secondary and primary sources and identifying further sources of literature continues until what Gratton and Jones (2004: 59) describe as ‘saturation’, where new sources being read are not identifying any useful sources that have not already been identifi ed during the literature search. Students will notice a diminishing return of new sources being identifi ed, the further they progress with their literature search.
Sources of performance analysis research
Performance analysis of sport has its own specialist journal and there are four key textbooks in the area. The performance analysis community have met every two years or so at their series of World Congresses where research is presented and discussed. The proceedings of these World Congresses have been written up as books, allowing performance analysis students to rapidly survey a great volume of previous research. There are other journals, books and conferences that include performance analysis contributions and the main sources of performance analysis material is listed as follows:
Performance analysis journal:
• International Journal of Performance
Analysis of Sport.
Other journals that publish performance analysis research:
• Journal of
Science and Medicine in Sport, International Journal of Sports Science and Coaching, International Journal of Coaching Science, Research Quarterly for Exercise and Sport, Journal of Sports Science and Medicine, International Journal of Sports Medicine and Physical Fitness, Strength and Conditioning Journal, International Journal of Computer Science in Sport, Open Sports Science Journal, European Journal of
Sports Science, Journal of Human Movement Studies, Journal of Sports Sciences and Ergonomics.
Proceedings of the World Congresses of Performance Analysis of Sport,
•
which are published as books.
Notational analysis and performance analysis textbooks (Carling
• et al.,
2005, Hughes and Franks, 1997, 2004a, 2008).
Match analysis and biomechanics sections of Proceedings of World
•
Congresses of Science and Racket Sports and Science and Football, which are published as books.
Indirectly relevant material
Performance analysis of sport is an emerging discipline within sports science, which itself is a relatively new science. Therefore, there will be occasions where students are investigating important and interesting research ques- tions that have not been addressed before in any sport. Students addressing original problems will have diffi culty fi nding directly relevant academic lit- erature to use within the literature review and discussion chapters of their dissertations. In such situations, it is recommended that students draw on indirectly related academic literature. An example of this from the author’s own experience was when a colleague and the author came up with the idea to investigate the infl uence of score line on work-rate in FA Premier League soccer (O’Donoghue and Tenga, 2001). There was an abundance of aca- demic literature on the physical demands of intermittent high intensity activ- ity in fi eld games in general as well as on the demands of soccer match play in particular. There was also a great deal of previous research into time- motion analysis methods as an indirect observational way of estimating the demands of fi eld games. However, the researchers were unable to fi nd any literature on the effect of score line on work-rate in any sport. Indeed, the authors were not able to fi nd any previous research on the effect of score line on any aspect of performance in any sport.
The authors considered what score line at a given point in a match was;
they a considered score line to be a refl ection of the performance up to that point in the match. This allowed the authors to draw upon literature relat- ing to performance accomplishment. Bandura (1977) stated that perform- ance accomplishments were the most powerful source of effi cacy expectations.
A goal scored by a team is a performance accomplishment within a match that may, therefore, increase effi cacy expectation for the remainder of the match. The researchers also considered possible mechanisms by which work-rate could be affected by score line. If a player attributed the cause of the current game state (especially if the player’s team was losing) to factors outside the player’s own control, the player’s motivation may reduce. This speculation led the researchers to review sports psychology literature on causal attribution and motivation (McAuley, 1992, Weiner, 1985). The initial study done by O’Donoghue and Tenga (2001) found an effect of
score line on the percentage of time spent performing high intensity activity, but left the mechanisms involved as a ‘black box’ that future research could investigate.
This approach used by O’Donoghue and Tenga (2001) is recommended to students who have diffi culty fi nding previously published research that is directly relevant to their own research question. Students should consider the concepts involved in their research question and what general concepts within other disciplines of sports science might be related to them. Students may then identify literature from coaching science sources, sports psychol- ogy, biomechanics and exercise physiology that can be discussed in provid- ing a rationale for the research question.
Reading the literature
As has already been mentioned, this stage overlaps with other activities within the literature review and the student may read and record papers while there are still other articles to be identifi ed during the literature search.
When reviewing previous literature, the student should be as critical as pos- sible, identifying strengths and weaknesses of previous research. This involves the following steps.
1. Read the title and the abstract to gain an overall synopsis of the purpose of the paper, what was done, what was found and what was con- cluded.
2. If the paper is of interest to the student’s research, then the reference details of the paper should be recorded so the student is able to include the paper in their own reference list. The student may not be able to make a decision about the relevance and usefulness of the paper to their own study after reading the abstract, so this step could occur later.
3. The need for the study as expressed in the introduction or background section should be considered.
4. The student should examine the stated hypotheses that outline the spe- cifi c research question being answered one way or the other by the paper. Often papers do not formally state hypotheses but instead set out the aims and purpose of the paper. No matter which style is used, the student should initially try to determine the research question being asked and the key variables involved.
5. The student should look at what the study found by examining the results section. The results may agree with or contradict those of other studies that the student has read. The results may be consistent with some theories but not others. These observations should be noted by the student so they are not only considering the paper in isolation, but the review of literature begins to identify patterns and debates within the research area.