--- title: "Semantic web use, purpose and need" subject: "Web Technology" chapter: 9 key: "semester_7/web_technology:semantic-web-need-use" source: https://www.bctengineer.com/q/semester_7/web_technology/semantic-web-need-use site: BCT Engineering --- # Semantic web use, purpose and need Web Technology · Chapter 9: The Semantic Web - Asked in: year not given, 8 marks - Video: [Intro to the Semantic Web](https://www.youtube.com/watch?v=OGg8A2zfWKg) — Manu Sporny - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_7/web_technology/semantic-web-need-use - Whole chapter: https://www.bctengineer.com/md/semester_7/web_technology/chapter-9 ## Question What is semantic web? Explain the use and purpose of semantic web. Why it is needed in present web? Give your own reason with example. ## Short answer The Semantic Web extends the current web with machine-readable meaning to support better search, data integration, and intelligent agents. It is needed because today's web is mostly human-readable, leading to ambiguous keyword search and manual data combination; semantic markup allows precise, automated queries. ## Answer #### Semantic Web The **Semantic Web** is an extension of the existing Web, proposed by Tim Berners-Lee, in which information has a well-defined, machine-readable meaning. Data is described with RDF, ontologies (OWL), URIs and metadata so that software can interpret it, link it and reason about it. It is "a web of data" rather than a web of documents. #### Use and purpose - **Better search:** Meaning-based search returns precise results instead of pages that merely contain the keyword. - **Data integration:** Data from different websites and databases can be combined automatically (Linked Data). - **Intelligent agents:** Software can plan trips, compare products, schedule meetings and answer questions for users. - **Knowledge sharing and reuse:** Ontologies give common vocabularies for fields such as health, education and e-government. - **Automation:** Reduces manual work in collecting and processing web information. - **Personalisation and recommendation:** Suggestions based on the user's understood interests. #### Why it is needed in the present web 1. Today's web pages are written for humans; computers see only text and tags. 2. Keyword search is ambiguous: "Python" may be a snake or a language, and search results contain much irrelevant material. 3. Information is scattered over many sites in different formats, and combining it needs manual effort or custom programs. 4. The amount of data is growing so quickly that people cannot process it without machine help. #### Example (own reasoning) A student in Nepal wants "a government-approved engineering college in Pokhara with a computer course and a fee below Rs 5 lakh". At present, the student must open many sites and compare them by hand. If colleges publish their data with common semantic markup (type: College, location: Pokhara, program: Computer, fee), an agent can query all of them with SPARQL and list the matching colleges in seconds. Similarly, in medicine an agent could link a patient's symptoms with disease data from many hospitals. Thus the Semantic Web is needed to make the growing web searchable, connected and useful to both people and machines. ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. Why is the Semantic Web needed in the present web? A. Pages are written for humans, so computers see only text and tags B. Computers already understand all pages C. The web has too little data D. HTTP is not supported Answer: A. Present pages lack machine-understandable meaning, so software cannot interpret them. (Key point: Why needed) 2. Which problem of keyword search is illustrated by 'Python'? A. Too few results B. Ambiguity: it may mean a snake or a language, with many irrelevant results C. Slow servers D. Missing images Answer: B. Keywords cannot distinguish meanings, giving irrelevant results. (Key point: Ambiguous search) 3. What does Linked Data / data integration allow? A. Data from different websites and databases can be combined automatically B. Websites to copy designs C. Deleting old data D. Faster typing Answer: A. Common semantic markup lets data from many sources be combined automatically. (Key point: Data integration) 4. In the Pokhara college example, how does the agent find matching colleges? A. Opens each site and compares by hand B. Queries all colleges' semantic data (type, location, program, fee) with SPARQL C. Asks the user to type each fee D. Uses image search Answer: B. Common semantic markup lets an agent query all colleges and list matches in seconds. (Key point: Intelligent agent example) ## Related in Web Technology - [Semantic web and its purpose](https://www.bctengineer.com/question.md?key=semester_7%2Fweb_technology%3Asemantic-web-purpose-example) — Web Technology, chapter 9, asked 3× - [Main aspects of the Semantic Web](https://www.bctengineer.com/question.md?key=semester_7%2Fweb_technology%3Asemantic-web-aspects) — Web Technology, chapter 9