Review of Literature

Concept

A literature review surveys and critically evaluates what is already known about the topic. It helps the researcher avoid duplication, discover the research gap, sharpen the problem and hypotheses, build the theoretical framework, learn which methods and tools worked, and compare later findings with earlier ones. A good review is relevant, current, organised thematically or chronologically, critical rather than merely descriptive, and ends by showing what is missing. It begins early but continues throughout the study. A research gap is a question that earlier studies left unanswered or answered inadequately.

Concept

Primary literature reports original research or ideas for the first time: research articles, theses, conference papers, patents and technical reports. Secondary literature interprets or summarises primary work: review articles, textbooks, encyclopaedias, handbooks and yearbooks. Tertiary sources help you find the others: indexes, abstracts, bibliographies, directories and databases. Grey literature includes reports, working papers and theses that are not commercially published.

Concept

Effective searching starts with keywords and their synonyms. Boolean operators combine terms: AND narrows the search (both terms must appear), OR broadens it (either term, useful for synonyms), and NOT excludes a term. Truncation (for example educat*) finds word endings, wildcards replace single characters, and quotation marks search an exact phrase. Field searching, filters for date and type, and controlled vocabulary or thesaurus terms (such as MeSH in medicine) refine results. Citation chaining follows references backward and citations forward from a good paper.

Concept

Shodhganga is the national repository of Indian electronic theses and dissertations (ETDs), maintained by the INFLIBNET Centre, Gandhinagar, an inter-university centre of the UGC. UGC regulations require universities to deposit the electronic copy of every approved doctoral thesis there. Shodhgangotri holds synopses of research topics from registered scholars. Other INFLIBNET services include e-ShodhSindhu, the consortium for electronic resources, and Vidwan, the database of experts. Searching Shodhganga shows what Indian doctoral work already exists on a topic.

Concept

A narrative review summarises a field selectively. A systematic review follows an explicit protocol, searches comprehensively, applies stated inclusion criteria and appraises quality, often reported by PRISMA guidelines. A meta-analysis statistically pools effect sizes across studies. A scoping review maps the extent of literature. Journal quality is often judged by metrics. The impact factor (Clarivate’s Journal Citation Reports) is the number of citations in a year to items published in the previous two years divided by the number of citable items in those years. CiteScore (Scopus) uses a four-year window. The h-index (Hirsch, 2005) is the largest number h such that the author has h papers each cited at least h times; the i10-index counts papers with at least ten citations.