How and where to look for information for a thesis
Starting a doctoral thesis is no less than an adventure. Expanding the barriers of human knowledge is one of the most rewarding tasks that can be carried out at the Academy. But it is also a titanic task, qualitatively and radically different from what can have been done so far at the Undergraduate and Master levels. Therefore, it is not usual to feel disoriented and lost in the first steps of this new stage.
This text is intended to be of help to all those students who start their doctoral thesis and who are in the first intellectual steps of all research: to locate themselves in the study area and define what is known about the subject of the thesis and what could be investigated about.
In essence, this short manual aims to make you understand the following questions:
1. Why is not any document useful to support my thesis?
2. Where can I find the documents I need for the thesis?
3. How can I locate those documents? That I have to do?
Each of the three chapters below will answer one of these questions.
I want to show in this text a particularly didactic and useful zeal, although sometimes it lacks terminological rigor. I write from my experience as a researcher and consumer of scientific information, but I do not belong to Documentation Sciences. However, I hope that my fellow documentary makers will forgive me for this intrusion into their domains: I do it without malicious intent.
Finally, I hope that this document will be expanded and modified in the future. If you consult it and read it, I would appreciate it if you leave me a comment in my email (stopthatskhan@gmail.com). All opinions will help improve.
Formats and supports of scientific information
This topic covers the birth and development of the scientific article as the main current form of transmission of knowledge within the academy and the research field. Other types of supports and documents are also presented, which, with less relevance, are relatively common in certain scientific disciplines.
Specifically, the following objectives are set:
• Become familiar with the main formats of scientific communication today
• Know the reasons why the scientific article is the main support for contemporary scientific communication.
The scientific article
The communication of the results of experiments and other studies is an indispensable part of the scientific research process. There is no point in testing a theory, refuting a hypothesis, or solving a conjecture if this advance in knowledge is not made available to members of the scientific community.
One of the first means by which new ideas were transferred to colleagues was through books, first manuscripts and then print, after the arrival of Johannes Gutemberg's invention.
Some examples in this sense can be Plato's dialogues, the Discourse on the Descartes Method, or the Sidereus Nuncius (1610) by Galileo Galilei.
However, since the Renaissance and with the improvement of road infrastructures and regular postal service establishments, another means of scientific communication appears that will become especially relevant: the sending of letters between colleagues in the same discipline.
One of the most relevant examples of the importance of epistolary communication for science is found in the figure of Gottfri ed Wilheim Leibniz. The philosopher and mathematician is credited with more than fifteen thousand letters written and sent to thousands of different recipients, among whom were the great philosophers and mathematicians of the time such as Johann Bernoulis, Vincent Placciu s or Antoine Arnauld.
This boom in postal communication converges with the establishment of the first scientific journals in the 17th century. In this period, scientists begin to organize around academic societies to facilitate the discussion and sharing of the main scientific findings and theories of the different disciplines.
These societies promote the publication of periodicals with the idea that it is much more effective to "centralize" the reception and distribution of texts than the model of communication between several colleagues in isolation.
For example, if a member of the Royal Society of London wanted to communicate the results of an experiment, it would be more efficient for them to send the text to those responsible for the association, the scientific society grouped it with the submissions of other scientists and published them together in a periodic newsletter that will be distributed to all members. `
This new model has gradually imposed thanks to this efficiency and cost savings. These publications will be the direct antecedent of current scientific journals, which are the main means for scientific communication on a temporary basis.
What is the reason for this rise in scientific journals? In large part, the introduction of a "peer review" process, which ensures a prior evaluation of the article or text before acceptance for publication.
This peer review, a priori, filters those articles that do not provide significant news, that have deficiencies in the methodology or that are otherwise deficient. In other words, this review process guarantees the quality of the articles published in these journals (Harnad, 1998).
The rise of publishing and publishing of scientific journals raises a question: how can we identify the journals that publish the best articles and the best contributions to the respective scientific disciplines? As we will see in the next topic, products such as Web of Science or Scopus will emerge to evaluate and identify the best journals within each scientific field.
This evolution of scientific journals and the products for their evaluation implies in practice a fundamental truth that must be known by anyone who aspires to carry out scientific research in the academic field: what is not published in indexed journals (in Web of Science or Scopus) either does not exist or is not relevant.
What is the reason for this restriction? The volume of scientific production has progressively skyrocketed throughout the 20th century, reaching almost impossible sizes to be handled by a single individual without the need for secondary filters or evaluations.
To give an example, in the field of Sociology in 1960 about two thousand articles were published. That figure has been progressively multiplied until exceeding ten thousand articles in 2010.
This increase in scientific production means that, as a general principle, researchers' attention is focused on what is published in journals indexed in these databases. Furthermore, the journals themselves value that the discussion and theoretical foundation be based on works published in journals that are also indexed in these databases.
Finally, the professional evaluation of the researchers also prioritizes the works that are accepted and published in these journals.
For all this, it is essential to read works published in indexed magazines and aspire to have our own works published by these magazines.
As a general rule, almost all major indexed journals are published in English. With the exception of isolated, specific, and very specific exceptions, the language in which contemporary scientific discussion takes place and in which the main advances and results of the research are proposed in English.
The command of English as the main language for scientific knowledge is not limited only to the natural sciences and the social sciences, but since the 70s it has also been expanding to the Arts and Humanities (Liu, 2017).
No work or author can be considered minimally familiar with the state of the art of their discipline or research topics if they turn their back on English.
Beyond the scientific article
However, the scientific article is not the only format in which the theories and study results are distributed and communicated. It is the fundamental and the most important, as we have already underlined, but there are other modalities that are relatively relevant in certain aspects or fields of knowledge.
In this sense, the main exception to the intellectual preponderance of scientific journals is found in some disciplines with a more humanistic orientation (such as History, Philosophy or Literature), in the Legal Sciences and, to a lesser extent, in some areas of the Social Sciences. In these fields, books, especially large monographs, continue to be especially relevant and share prominence with scientific articles.
The fact that books constitute an adequate and accepted reference in these areas does not imply that any book can be cited. It is advisable not to cite subject manuals as well as reference works such as dictionaries or encyclopedias.
It is understood that these types of works have an informative or educational objective and, therefore, do not include relevant research results and
They should be avoided in a thesis or any other research paper.
The conference proceedings enjoy special relevance, especially in Computer Science. In fact, some conferences have a similar consideration to scientific journals and are included with them in selective databases. This is due, in part, to the fact that the process of publication of minutes is faster than that of journals and therefore allows the latest research results to be disclosed without risk of the data becoming obsolete.
But this immediacy of the conferences would not be useful if it were not for the fact that the most relevant conferences also establish a peer review system similar to that of scientific journals. This process guarantees the screening and supervision of the research results that are transferred to the scientific community through this medium. However, there are tens of thousands of conferences that do not provide any kind of value and that accept and publish any proposal they receive.
Another modality that has gained relative importance in the last decade is the Working Papers. These are words or texts that are directly uploaded to the Internet by the author or authors, without prior revision. It is a still marginal modality but it allows to transfer preliminary results or works in their initial phases immediately so that they can be consulted and communicated by other colleagues.
However, as a reminder, it is worth not losing sight that the basis on which contemporary scientific knowledge is based is that of the scientific article. This implies that the references on which all work and even our own curriculum vitae must be built are scientific articles. Other formats (working papers, conferences) are secondary and considered of little value.
As a general rule, everything that does not pass a peer-review process it has no place within the research activity.
Summary
• The academic journals are the main vehicle for the transmission of scientific knowledge today
• The main scientific journals are indexed in databases such as Web of Science or Scopus
• The theoretical foundation and the state of the question should be based mainly on works published in these magazines.
• The main scientific language today is English.
Main Databases for Scientific Research and Articles
This topic presents the main databases and resources through which to consult the references for scientific articles and other works. It begins by paying attention to large databases of citations such as Web of Science and Scopus. In the same way, other specific databases (Medline) and new products such as Dimensions will be presented. Mention will also be made to academic search engines (Google Scholar and Microsoft Academic).
The objectives of this topic are:
Know the major databases
Present the most popular academic search engines
Prioritize these resources as sources of consultation
Bibliographic databases
Web of Science
Web of Science, formerly known as Web of Knowledge, was created by scientist Eugene Garfield in the 1960s. This initiative emerged as an attempt to create a database that includes the titles, abstracts, and keywords of published articles. in the main scientific magazines of the moment.
The novelty of this product consisted of adding, in addition, the information of the citations received by each article.
Web of Science does not include the full texts of the articles. It allows us to consult the title, the summary and the keywords of each job and offers the data that allow locating each reference (article name, number and volume of the magazine, year of publication, pages). To consult the complete work, you must go to the specific magazine that published the article. However, the latest versions of Web of Science allow that if accessed from the Library you can access the resource if the Library is subscribed to the magazine.
Each scientific article always includes a list of cited references, that is, of works whose ideas or evidence support the research carried out. Garfield includes these references in the database, allowing to trace the conceptual relationships between different works and the influence of work on subsequent works.
In Garfield's words, “citations are formal and explicit links between articles that have particular points in common. A citation index [like Web of Science] is built from these links. Lists publications that have been cited and identify the sources of those citations. Anyone doing a bibliographic search can find from one article to dozens of additional articles on the same subject knowing that they have been cited by an article. And each of these articles offers a list of new cited works with which to continue the search.
On the other hand, the information from the citations received also allows evaluating the relevance or influence of each article on a given issue. For example, an article that has been cited in a hundred other papers will be more relevant and important than one that has never been cited. In fact, Garfield's other great innovation is to use the information from the citations received by each article to evaluate the journals from the different scientific areas.
The initial goal of Garfield with this database was to manage and provide the information needed to measure the influence of articles and magazines in which they were published. For this, he developed the index dubbed "Factor Impact."
The Impact Factor is a quality index that calculates the average number of citations received by articles published in a magazine. For this, it takes into account the set of all articles published over a year and the total number of citations that these articles receive in the two years following their publication. For example, the Impact Factor of 2019 includes all the articles published by a magazine in 2018 and 2017 and divides them by the number of times those articles have been cited in those same years 2018 and 2017. In 2018 the magazine with the highest Impact Factor was CA: A Cancer Journal for Clinicians, with an index of 223,679. This indicates that each article published in 2016 by this magazine was cited a total of 223 times in 2016 and 2017.
Bases of data Web of Science:
Web of Science is built on a group of different databases that include different sets of documents depending on the discipline they belong to, the geographical area, the type of document or other categories.
• Discipline-specific databases
• Science Citation Index Expanded (SCIE). This is the original database from which the Web of Science was built in 1964. The rest of the databases will be added later. SCI includes journals in experimental science, biomedicine, engineering, and mathematics. It covers more than nine thousand magazines and fifty-three million articles published from 1900 onwards
• Social Science Citation Index (SSCI). It is the Web of Science database dedicated to the Social Sciences, such as Education, Sociology, Communication or Documentation. It is made up of 3,400 magazines that have published nine million articles
• Arts & Humanities Citation Index (A&HI). This database includes articles published in magazines of Humanities and artistic disciplines. It is made up of almost five million articles published since 1975 in eighteen hundred different magazines
• Current Chemical Reactions and Index Chemicus. Specialized databases in Chemistry.
• Specific databases of publication formats
• Book Citation Index (BKCI). It offers information on more than one hundred thousand books published from 2005 onwards.
• Conference Proceedings Citation Index (CPCI). It includes more than two hundred thousand conference proceedings held since 1990.
• Specific databases by geographic area
• SciELO Citation Index. It is built on the magazines included in SciELO, an online open-access platform for Latin American, Caribbean, Spanish, Portuguese and South African magazines.
• Korean Citation Index. Dedicated to magazines published in Korea
• Russian Citation Index. A database built on Russian magazines.
Emerging Source Citation Index (ESCI). It is one of the most recent Web of Science databases. The coverage of Web of Science is increasing with journals of increasing importance, which can be considered as “candidate” journals to access SSCI or SCIE.
ESCI is considered a “second division” of Web of Science, so journals that achieve a certain level of citations can go from ESCI to SCIE or SSCI. This was, for example, the case of Digital Journalism, a magazine included in ESCI in 2017 and included in SSCI in the 2018 edition.
In parallel, it is considered that SCIE or SSCI journals that cease to have a certain impact, can descend to ESCI.
Inclusion and exclusion criteria in Web of Science
The journals included and candidates to be included in Web of Science must meet a series of requirements, including:
Peer review
Web of Science only includes journals that submit submitted articles to a prior peer-review process.
Formal criteria
Journals must meet a series of formal requirements ranging from the web presence of the editorial committee to the inclusion of abstracts and keywords in English and the presence of the affiliation and contact details of the authors of the published articles.
Respect for periodicity
Web of Science requires that the periodicity of the journal be observed. Let’s say a title promises to come out four times a year in January, April, July, and October. In the event that this journal publishes three issues a year instead of four or that instead of publishing its winter issue in October it does so in December, this may be a reason for exclusion from Web of Science. It is understood that failure to comply with this periodicity may be due to not receiving enough manuscripts and that, therefore, the editors of the journal may be forced to accept articles without sufficient quality to reach the planned periodicity.
However, inclusion in the Web of Science is not eternal and unconditional. Indexing in the database is subject to impact criteria and good practices.
Thus, one of the reasons for being expelled from Web of Science is the repeated absence of impact. It is understood that if a magazine does not receive citations in two years in a row, it has lost relevance in its area and, therefore, it has ceased to meet the demand for quality and impact expected of the publication. As an example, we can cite the case of the journal Comunicación y Sociedad, which was included between 2010 and 2012 in the Science Citation Index, but when it stopped receiving citations, it was excluded from the database in 2013.
The other reason a journal can be kicked out of Web of Science is the accusation of unethical practices. For example, the magazine Cereal Research Communications was excluded two years (2008 and 2009) from SCI for presenting a percentage greater than 90% of self-citations (that is, of citations of articles published in the journal to other articles published in the same journal)
These types of practices are persecuted and punished by those responsible for Web of Science because they consider that either the influence of the journal is non-existent outside the articles it publishes (because they fail to attract the attention of other researchers or articles published elsewhere. magazine) or because one senses the existence of pressure on the part of the editor so that the articles published must include a certain number of citations to the magazine itself.
Web of Science held a monopoly on citation rates until 2004, when the publishing group Elsevier launched its first major competitor: the Scopus database.
During its first ten years of existence, Scopus argued that its greatest advantage over Web of Science was its greater coverage. The new database boasted that it included more Social Sciences and Humanities journals than Web of Science. He also argued that, in addition, he indexed more documents in languages other than English, especially in the case of Spanish.
Starting in 2015, the Web of Science tried to compensate for these criticisms by increasing its range of journals by creating databases in other languages (Russian Citation Index, SciELO Citation Index, Korean Citation Index) and through the creation of other secondary databases such as ESCI.
Following these actions of Web of Science, its coverage, especially in terms of languages, has been comparable equably (Vera-Baceta, Thelwall & Kousha, 2019)
Alternative indexes to the Impact Factor of Web of Science are calculated from the Scopus data: the SNIP (Source Normalized Impact per Paper or SJR (SCImago Journal Rank).
The novelty of the SNIP is that it takes into account the average number of citations in discipline, so if in Chemistry the average number of citations for an article is 15 and in Sociology 3, compensation is made for SNIP of a journal of Chemistry and other of Sociology are comparable in relative terms. (Leydesdorff & Opthof, 2010).
As for the SJR, its novelty is that it gives a relative weight to the citations received based on the magazine, so it is not the same as an article being cited by the most important magazine in the area as Ca: A Cancer Journal as by a marginal magazine. (González-Pereira, Guerrero-Bote and Moya-Anegón, 20 10)
Unlike Web of Science, Scopus works with a single database, although it allows differentiating between types of documents so that it can be filtered by books, articles or conference proceedings
Dimensions
Dimensions is the youngest product among academic databases and is halfway between a database and a search engine.
Its main novelty is that it does not limit its information to that of citations received. Its database also includes links between articles with funded research projects, patents, clinical cases, or even mentions in the news or on social media.
It has a free version and a paid one. The free version allows searching by keywords and abstract or by the full text of the article. Thus, by including the full text of the article, it allows consultation in languages other than English, such as Spanish, French or Portuguese.
The free version of Dimensions can be accessed through the following link:
Academic search engines
Academic google
Google Scholar (or Google Scholar in English) is the version of the Google search engine aimed exclusively at retrieving scientific documents. Instead of searching for a text on the web in general, restrict the search to articles and other academic documents.
This search is performed in the full text of the documents. Unlike Scopus or Web of Science, Google Scholar is not limited to the abstracts and keywords of the articles but searches for the requested terms throughout the text of the documents.
By indexing the full text of the articles, you can consult in any language.
This full-text consultation is carried out regardless of whether the text is freely available or open on the Internet. Google has reached an agreement with the main publishers of scientific journals to allow full access to their search robots, but not to users.
Therefore, Google Scholar does not always offer open links to the document itself. If there is no open access version of the text available, the search result will redirect to the publisher's website, and if our library is not subscribed, we will not be able to view that article.
The downside of Google Scholar is that it is totally inclusive. In other words, its database is made up not only of articles in scientific journals but also of any document that respects the formal features of a scientific article (has a title, authors, abstract, keywords and list of references) or that is uploaded to an academic server or an institutional or thematic repository.
This inclusivity causes that its results appear without any differential ion journal articles quality work End of Grade and other texts without any guarantee of reliability.
Among other disadvantages of Google Scholar, it can be pointed out that it does not differentiate documents by areas of knowledge, geographical areas, or other factors. It only allows narrowing the search by years, author or specific magazines.
Access to Google Scholar is done through https://scholar.google.es/
Microsoft Academic
Like Google Scholar, Microsoft Academic is a search engine specialized in scientific documents. This is Microsoft's attempt to compete with Google in this area,
Unlike Google Scholar, it allows you to refine your search by research topics.
Another of its most useful features is to offer search suggestions. When you enter a term in the search bar, word suggestions or terms related to what you are typing auto-complete appear. For example, if we enter "social media" the search engine suggests related subjects such as "Social media optimization", "social media mining", or "social media marketing".
Summary
The bibliographic databases such as Web of Science or Scopus, selected research results published in the journals most relevant scientific and other sources that meet quality criteria
Within the bibliographic databases, the highest quality results are collected in the SCIE and SSCI of Web of Science
Conversely, academic search engines such as Google Scholar or Microsoft Academic do not screen or select the documents they offer when searching
In general, it is recommended that the greatest weight of an academic information search is focused on Web of Science and that, in a secondary way, it uses other sources such as Google Scholar
Document search strategies
This topic presents some of the main strategies for searching for documents in the databases mentioned in the previous topic. You will start by choosing a topic and from there will be successive delimitations of the search to reach a manageable size of references that can be consulted. Alternative strategies such as search by the author will also be suggested. Finally invite the student to consult especially useful items to be placed in a research topic for the first time as the análisi meta s, the review articles or items bibliometric.
In a synthetic way, it is intended to achieve the following objectives:
Define and document searches by keywords.
Use bibliographic information to broaden searches.
Know the use of meta-analysis, review articles and bibliometric studies to have a first approach to the field of study
First steps
When exemplifying the different steps of a search for information and documents, we will focus on Web of Science. These strategies are easily replicable in other environments such as Scopus or Google Scholar.
However, the first step in using Web of Science refers to one of its particularities. As we explained in the previous topic, Web of Science is itself made up of a set of databases. By default, Web of Science usually searches all of them. Search should be set so that it is restricted to the collection principal of the database.
In this way, we will not only be able to obtain more pertinent results and from higher quality journals, but also be able to use some options or functionalities that are not available in other databases.
To restrict the query, choose the option from the drop-down menu that appears on the initial page of Web of Science.
Once this configuration has been changed, we can follow various strategies to search for documents related to our object of study, as we will detail in the rest of the epigraphs of the topic.
Search by subject
If it is the first time that we are approaching a certain subject, it is advisable to start the search by defining the topic of interest.
This search works roughly the same as the Google search engine. That is, it is about entering a word or words and the Web of Science engine will retrieve all the references that include that term in their summary or among their keywords.
For example, if we introduce "Cancer" we will obtain the list of all the more than two million documents that mention this term in their summary or include it in their keywords.
Every time we click on the title of each of these results, we can consult its summary and, as we will see later in this topic, the references cited in that article.
It would be a clearly unmanageable volume of results and it is necessary to restrict. Nobody in their right mind would aspire to be able to read, albeit superficially and superficially, such a large number of documents. Next, we will see how you can filter results until they are reduced to a more reasonable size.
Keep in mind that the broader the concept we seek, the more results we will find and the less manageable the whole of the search. It is almost impossible to identify useful documents for our specific works among thousands or hundreds of thousands of references.
That being said, how can these documents be filtered? The first step in this regard would be to conceptually delimit the search term. In other words, being more restrictive and demanding that the results include more words.
Let's return to the example of Cancer. Suppose that what interests us is to study cancer prevention campaigns in the media. In that case, we could ask the database to retrieve all the documents that contain the words Cancer, Prevention and Communication (see Figure 2). In this way, we would eliminate the documents that, speaking about cancer, do not refer to prevention or communication.
Searching for documents that include the three terms yields less than two thousand results. It is a more manageable volume, but it would be necessary to continue restricting. We could also delimit by the type of cancer: lung cancer or lung cancer, breast cancer or breast cancer or by brain cancer or brain cancer.
In the end, the terms we choose should respond to our research interests.
The searches are to be mainly in English. Remember that Web of Science and Scopus primarily include the abstract and title in English of the articles, even though they were originally published in Spanish. That is why when you want to make a query you must do it initially through terms in English and then in Spanish.
The use of English terms, especially if we are not familiar with academic texts on the subject, can be complex the first time
The use of thesauri (such as http://www.thesaurus.com) can facilitate the identification of synonyms and terms related to the concepts we want to search for. Continuing with the example of the query on cancer prevention, we may be interested in finding synonyms for "prevention".
The results appear ordered from highest to lowest conceptual proximity, with the most relevant ones highlighted in dark orange and listed at the beginning. Thus, in the example that we propose, "avoidance" will be the term most similar to "prevention" and "deterrence" the least similar. If we did the search for "Cancer" we would find several related terms, some generic like "disease" and others more relevant like "tumor". From these terms we could carry out new searches such as "tumor avoidance" or "tumor prevention"
Search delimitation and restriction
To narrow the search a priori, all you have to do is enter all the words you want the documents to include.
As we have already said, you can also restrict searches afterwards. That is, we can further narrow the results after having done an initial search.
To do this, simply enter the search terms in the "Refine results" box that appears on the left side of the screen with the search results. This action would remove from the list of results all those that do not include the words that we enter.
If we continue with our example of cancer prevention, we can take advantage of restricting all those results that include the term "television". To do this we would only have to enter that word (or the ones we want) in the box.
It may happen that we are not interested in further restricting our search based on concepts or keywords. This can happen if we consider that the subject of the query is already defined and delimited and there is no point in further reducing that focus. How can we proceed to reduce or prioritize the results, if we continue to find an unmanageable number?
Web of Science allows screening or prioritizing the results following multiple criteria. From a practical point of view, the most interesting may be the date of publication and the relevance in the field, depending on the number of citations
Delimitation per year
Let's say now that we have redirected our search towards the relationship between cancer prevention and secondary education. We would have around three hundred results and we would not want to narrow the search further from a conceptual point of view.
We may be interested in restricting the consultation by years of publication so that we focus or can attend to the most recent results first.
In the field of natural and experimental sciences, works more than two years old are usually considered to have become obsolete. In the field of social sciences, this "useful life" of a reference is extended to five years. In any case, it is recommended that the bulk (around 60% or 70%) of the references be made up of articles from the last two years. This allows the discussion and theoretical interweaving of our work to be connected with the latest and most lively trends and questions in our discipline.
To restrict the results by the date we can also go to the left side column. We can mark the years that interest us and once marked, click on the "Refine" button.
This configuration is useful because it allows you to go backwards yielding on results pages until you reach years of publication periods that we consider too old. For example, if we get to page 15 of the results and see that we are already dealing with articles published in 2014, it would not be worth continuing to consult further back.
Delimitation by number of appointments
On the other hand, the Web of Science offers the functionality of ordering the results by the number of times they have been cited.
In this way, we can organize the results so that those who have been cited by a greater number of works appear in the first positions. This will allow us to identify those investigations that are more relevant or with greater repercussion and to which, therefore, we should pay special attention.
It is worth noting that the fact that they have been cited does not always necessarily mean that they are especially relevant to our object of study. Articles that address a question in a transdisciplinary way are often highly cited as they are consulted by authors from different areas.
Thus, if we return to the example of the search for cancer prevention secondary education, we can organize it in this way by clicking on the "Times quoted" option located above the search results.
Thus, as we have noted, the first result ("Use of cardiac rehabilitation by Medicare beneficiaries after myocardial infarction or coronart bypass surgery") belongs to a transdisciplinary field, but the following two results can be considered basic within the discipline since they save a relationship with education and disease prevention.
If the date of publication of these articles is consulted, it can be verified that they are works with several years of antiquity. It is often the case that the most cited articles have appeared many years ago, since as they have been published for more time they have been more consulted and, therefore, receive more citations.
To cushion this presence of very old articles, a combined restriction can be made. That is, you can select only the last years that interest you (for example, 2019, 2018 and 2017) and keep the order by a number of appointments. Thus we would have identified the most recent articles that have aroused greater interest in the subsequent bibliography.
In any case, identifying the most cited articles (even if they are old) can help us find related bibliography that has cited them in recent years, as we will develop in the last section of the topic.
Other Search Filters
Another particularly useful option to reduce the number of results in Web of Science, in particular, is to limit the query to the most restrictive databases. It is usually advisable to especially restrict the Science Citation Index, Social Sciences Citation Index and Arts & Humanities Index.
Once these options are enabled, you should go to the "Web of Science Index" option and refine using the databases we have mentioned.
Although this option is particular to Web of Science, there are other tips applicable to the rest of the databases that we have indicated. Practically all of them allow restricting searches by categories or research disciplines.
Let's say that our searches for cancer interest us from the point of view of Education. In that case, we should look for the "Web of Science Categories" option and select the research areas related to Education and, finally, press the "Refine" button
In this way, we would leave out articles published in magazines that are not included in the Education area.
We could also choose an inverse strategy that would be to choose the categories or areas of research that we are not interested in and leave them out. To do this, you would have to press the "Exclude" button instead of "Refine".
Web of Science and other databases such as Scopus also allows the results to be refined by other options such as "Country". Keep in mind that this filter refers to the country of the authors' institution, not the country in which an investigation is carried out or to which the sample analyzed in the study belongs.
Therefore, if we are interested in restricting only to studies on certain countries or contexts, it is preferable to include the name of the nation that we choose in the search terms by subject. For example: cancer prevention secondary education Spain.
Although all the instructions in this section have been exemplified with Web of Science, in section 3.8 ("Complementary material") you have at your disposal a guide of advice for the use of Scopus in which you will find instructions to adapt those searches to that environment. You will also find a video tutorial to familiarize yourself with the advanced options of Google Scholar.
Advanced search
For advanced searches, it is worth familiarizing yourself with Boolean operators, the use of quotation marks, and the use of wildcard characters.
Quotation marks
If we use quotation marks, we will ask the search engine in question to offer us the records that include the phrase as we enter it. That is, it will retrieve the exact words in the precise order in which we handle it. For example, if we enter "Secondary Education" we will only get the results with that exact phrase. We would leave out, for example, those who talk about "secondary skin cancer prevention" and "education".
This functionality is very useful to identify a concept formed by two or more terms and allows to leave records where the two terms appear, but without relating to each other.
Boolean operators
Boolean operators (also known as symbolic logical operators) are named after the English mathematician George Boole. These are instructions that allow for more precise searches based on the relationship between different terms.
To use a boolean operator, just enter it -always in capital letters- in the search box
The main Boolean operators are cited and exemplified below
AND. It is the default function that is included in the search box. If we search for several elements, the search engine understands that all the terms entered must be searched. It is the same to introduce cancer prevention communication as Cancer AND prevention AND communication
OR. This function makes the database search for any of the entered words. For example, we can search for articles that talk about cancer or tumor at the same time using the formula tumor OR cancer
NOT. It allows excluding the words that we indicate. For example, "cancer prevention" NOT chemotherapy would leave out all documents that include the term chemotherapy
SAME. Requires that the terms indicated appear in the same sentence. For example: Cancer SAME prevention
NEAR. It allows you to search for documents that contain terms separated from each other by a certain number of words. For example, the Cancer NEAR / 3 Prevention order would search for documents in which both terms are separated by a maximum of three words (whether or not they are in the same sentence). We can modify the number of words of separation between the two terms by modifying the number that appears after the bar. However, the higher that number, the less relevant the relationship between the indicated words will be.
In section 3.8 (" Supplementary Material") you will find a visual guide to the main Boolean operators. But keep in mind that not all of them are used in all the databases we are using.
Wildcard characters
They are also known as " truncation operators". They allow entering generic characters so that the search engine interprets that we want to retrieve all the variants of a word.
The main operators are truncation asterisk (*) and the closing interrogac ion (?)
The asterisk (*) indicates that one letter, several letters, or none can appear instead. For example, if we search psycholog * the engine will retrieve all the results that include terms like "psychology", "psychologist",
"psychologists", "psycological" and any other derived from the root "psycholog-"
For its part, the closing question mark (?) Indicates that it only substitutes one letter. Thus, if we introduce the term m? N we will search for both the word "man" and its plural "men" (and, if they existed, words such as "min", "mon" or "mun")
There is a third wildcard term that is the dollar symbol ($). This replaces a character or no character. It is unlike the asterisk that cannot be replaced by more than one character. Thus, the search exam $ will retrieve documents that include the word "exam", the plural "exams" but not derived words like "examination".
Citation search cited references and review articles
Once the articles that are most relevant or closest to our research interest have been retrieved and identified, it is advisable to continue searching for material by reviewing the bibliography cited in those same works.
The databases allow consulting this list of references without having to go to the original text. To do this, in Web of Science you would have to click on the file title and once on the reference card, click on the number that indicates the cited references that appears on the right of the screen
Consulting this list of references is especially useful and advantageous. If an article that we have identified approaches our object of investigation, it is very likely that he, in turn, would turn to work that may be of interest to us. Consulting the works cited by these authors can put us on the track of articles of interest for our research.
We can also follow the reverse path. That is, we can identify articles that have cited works aligned with our research interest. For example, if we find a certain study that is useful for our work and we see that it has been cited by other articles, it is not unreasonable to think that these other articles may show interest that is common to us or be relevant in some way.
You can access the list of articles citing directly from the list of references. To do this, simply click on the number that indicates the number of times that the document has been cited. Obviously, if an article has never been cited, we will not be able to consult any list of citing articles
Most resources - not only in Web of Science or Scopus, but also Google Scholar and Dimensions - allow identifying the articles that cite a reference. Reviewing the works that have cited those texts that have interested us may allow us to discover new references or documents aligned with our research and useful for our work.
Finally, it is advisable to search for meta-analysis, review and bibliometric articles on our research topic.
The first type of work ("meta-analysis") develops a statistical analysis of the results of previous studies on the same question (Lipsey & Wilson, 2001), so that they compare and contrast -for example- the relationship between two factors (such as between tobacco use and lung cancer) or the efficacy of a treatment (such as homoeopathy in certain diseases) based on the treatment of the data reported in all the previous studies. These types of studies are widely used in Medicine and begin to be habitual - timidly - in other Social Sciences disciplines such as Education or Sociology.
The review articles, on the other hand, present a complete and systematized state of the question about a given research topic. Their approach is more qualitative than quantitative and they determine which are the great debates and questions that are the subject of a particular field and, in the same way, they highlight or point to possible new lines of research.
Finally, the bibliometric articles carry out a quantitative analysis on formal aspects (authorships, keywords, cited references...) of a set of scientific works, so that they allow identifying the features that have shaped a field of study and identifying possible new lines of research (Santa Soriano, Lorenzo Álvarez & Torres Valdés, 2018).
These exploratory practices (consultation of references in an article, search for cited references and search for review articles) are especially useful and recommended when choosing or delimiting a research topic or trying to define a thesis proposal or any another project that we approached for the first time as researchers
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