Before 1980s, the information and knowledge were stored in printed documents. These documents are evaluated, collected, stored and retrieved from library and information centres in which different measures like abstracting, indexing, consolidation, repackaging etc. are applied in order to arrange and retrieve documents. However, these complicated mechanisms are difficult for users to understand and use. On other hand, finding the required information was very difficult due to lack of channels of communications, high cost and less precision and recall. For proper access to required information, library professionals used to provide user education to instruct and guide users. Recently, the advancement of ICT, improvements in sophisticated infrastructures, and use of digital devices and internet etc. have laid information overpopulation. Notwithstanding, the opportunities of ease in access to information come with the challenges to sort and select the right and quality information. Due to easy and flexible access to huge amount of information via variety of applications and channels used to process and distribute, the users are facing challenges to retrieve right information at right time from right source. It is required to be able not only to search the required information but also to evaluate the relevance, accuracy, reliability, and currency of the information and the source. The skills and knowledge to locate, retrieve, evaluate, and use relevant information constitutes information literacy (IL). Julien and Barker (2009) defined the term "information literacy" is as the set of skills required to identify information sources, access information, evaluate it, and use it effectively, efficiently, and ethically (Julien & Barker, 2009).
In present information society, everyone, from novice to expert, from layman to professional, from students/researchers to professors, from farmers to scientists, from buyers to lawyers, from bankers to businessmen, and from politicians to army, are required to be informed. Information became worth and wealth. One who is information literate have more powers than others. On other hand, individuals having no IL Skills have lack of information, dependency upon others to get information, and even to acute levels of information anxiety. IL is important due to its potentiality to optimize the use of available information and to transform the novice into self-directed lifelong learners. Thus, information literacy skill is required by all concerned with every quantum of knowledge worldwide like from farming and horticulture to business and commerce, from aviation to shipping, from banking to life insurance, from health care to court of law (Majumdar & Singh, 2007). IL researchers and practitioners are engaged in development of models, designs, tools, standards, guides and frameworks, course instructions, etc. for enhancing IL skills as well as evaluation, assessment and impact of these in every subject fields. The IL research publications are spread out in large number of major and minor disciplines. The present paper employs co-occurrence network analysis to examine the evolution, current trend and research gaps in respect of disciplines engaging in global IL research and practice as well as intellectual base of IL publications. The finding of the study might be beneficial not only for global perspectives of IL research, but also for librarians, researchers, practitioners and policy makers in order to planning for assessment and provision of IL for those concerned with any segment of world of knowledge.
2 Review of Literature
Bruce (2004) stated information literacy as "a natural extension of the concept of literacy in our information society, and information literacy education is the catalyst required to transform the information society of today into the learning society of tomorrow" (Bruce, 2004). Information literacy comes with several other literacies which are individually or collectively used for IL viz., computer literacy, digital literacy, hyper-literacy, information technology literacy, interactive literacy, Internet literacy, library literacy, media literacy, multiple literacy, network literacy, oral literacy, and visual literacy etc. (Bawden, 2001; Dhiman, 2006). The critical review of the IL publications in different disciplines is imperative for the present study. At the same line, Ferguson et al. (2016) assessed IL competence of biology students (Ferguson, Neely, & Sullivan, 2016) and recognized the importance of awareness about IL among students. Moreover, the same is assessed in the field of Agricultural Sciences (Singh, 2015), Engineering (Alii & Abu-hassan, 2009), Library and Information Science (Islam & Tsuji, 2010), and Biosciences (Biradar & Swapna, 2011) etc. Similarly, IL competence is found vital ability for professionals related to Medical Profession (Lata & Sharma, 2013), Management (Kirk, 2004), Disability (Nanda & Ramesh, 2012), Pharmaceutics (Bawden, Devon, & Sinclair, 2000), Company Audit (Cheuk, 2000), Statistics (Cliftlands, 2005), Firefighting (Lloyd, 2005).
Based on the classification of subject categories in the Journal Citation Report of WoS, Hariri, Shekofteh and Yekta (2008) conducted subject category co-citation network analysis of journals publishing medical sciences in Iran and concluded the strong relationship between Multidisciplinary Sciences and Medical Sciences (Hariri, Shekofteh, & Yekta, 2008). However, Yao et al. (2013) visualized the subject category co-occurrence network of publications of translational medical research and examined the graph-theoretical property of nodes and found Research & Experimental Medicine, Medical Laboratory Technology, General and Internal Medicine is outstanding. Meanwhile, Oncology, Neurosciences & Neurology, Pharmacology & Pharmacy, Cell Biology, Biochemistry & Molecular Biology, Immunology in most central position and playing key role in the development of translation medical research (Yao, Lyu, Ma, Yao, & Zhang, 2013). Similarly, Zhu and Guan (2013) critical examined the subject category co-occurrence network of innovative research and found 48 subject categories in the field in which Business and Economics, Engineering, Public Administration, Operations Research and Management Science, and Computer Science are recognized as the core subjects (Zhu & Guan, 2013). Consequentially, Yao et al. (2014) analysed subject categories co-occurrence network of the Health System Research publications and recognized Public, Environmental and Occupational Health, Health Care Sciences and Services, and General & Internal Medicine as core subjects while nursing, pharmacology and pharmacy, and surgery are also playing key role in the research field (Yao et al., 2014). Moreover, subject co-occurrence network analysis is also applied in Innovation System Research (Z. Liu, Yin, Liu, & Dunford, 2015), Agriculture (Bartol, Budimir, Juznic, & Stopar, 2016), and Global Value Chains (GVC) (L. Liu & Mei, 2016).
3 Data and Methodology Applied
3.1 Data Set
Besides of various data gathering techniques like questionnaires, interviews, observations, archival records, experiments, etc., archival records are most suitable for the studies based on both scientometrics and social network analysis (SNA) due to less labor-intensive and least confusing (Milojevic, 2014). Thus, data collected from records archived in bibliographic databases are found purposeful for the study. In this regard, within top three bibliographic databases viz. Web of Science (WoS) of Thomas Reuters, Scopus of Elsevier, and Google Scholar from Google, Scopus is claimed as the largest abstract and citation database of peer-reviewed literature e.g. scientific journals, books and conference proceedings ("About Scopus," n.d.). It is an international multidisciplinary database indexing over 19000 international peer reviewed journals in all subjects, besides more than 500 international conference/seminar proceedings. Due to its wider coverage to the work of knowledge, Scopus data is assumed to generate a better picture of IL literature in the global context and hence found suitable for this study (Gupta & Dhawan, 2009).
Since, IL is used for same concept with several other names worldwide. In order to get full coverage of the IL research and practice literature, we opted advance search method to retrieve IL research articles published during 2001-16. The search string used is:
(TITLE) "information literacy" or "digital literacy" or "media literacy" or "computer literacy" or "infoliteracy" or "informacy" or "information empowerment" or "Information competency" or "information competence" or "information...