Editing Search engine (computing) (section)

==History of search technology==
{{further|History of web search engines|Timeline of web search engines}}

===The Memex===
{{Overly detailed|section|date=January 2021|details=hypertext-based search ranking applies to a small subset of search technology; details about the history and implementation of Memex are not relevant.}}<!--It's probably best to merge most of the section with [[Memex]]-->
The concept of hypertext and a memory extension originates from an article that was published in ''[[The Atlantic Monthly]]'' in July 1945 written by [[Vannevar Bush]], titled "[[As We May Think]]".  Within this article Vannevar urged scientists to work together to help build a body of knowledge for all mankind. He then proposed the idea of a virtually limitless, fast, reliable, extensible, associative memory storage and retrieval system. He named this device a [[memex]].<ref>{{cite journal|last1=Yeo|first1=Richard|title=Before Memex: Robert Hooke, John Locke, and Vannevar Bush on External Memory|journal=Science in Context|date=30 January 2007|volume=20|issue=1|page=21|doi=10.1017/S0269889706001128|doi-broken-date=29 January 2025 |hdl=10072/15207|s2cid=2378301|hdl-access=free}}</ref>

Bush regarded the notion of “associative indexing” as his key conceptual contribution. As he explained, this was “a provision whereby any item may be caused at will to select immediately and automatically another. This is the essential feature of the memex. The process of tying two items together is the important thing.<ref>{{cite journal|title=Before Memex: Robert Hooke, John Locke, and Vannevar Bush on External Memory|journal=Science in Context|date=30 January 2007|volume=20|issue=1|pages=21–47|doi=10.1017/S0269889706001128|hdl=10072/15207|postscript=The example Bush gives is a quest to find information on the relative merits of the Turkish short bow and the English long bow in the crusades|last1=Yeo|first1=Richard|doi-broken-date=29 January 2025 |s2cid=2378301|hdl-access=free}}</ref>

All of the documents used in the memex would be in the form of microfilm copy acquired as such or, in the case of personal records, transformed to microfilm by the machine itself. Memex would also employ new retrieval techniques based on a new kind of associative indexing the basic idea of which is a provision whereby any item may be caused at will to select immediately and automatically another to create personal "trails" through linked documents. The new procedures, that Bush anticipated facilitating information storage and retrieval would lead to the development of wholly new forms of the encyclopedia.

The most important mechanism, conceived by Bush, is the associative trail. It would be a way to create a new linear sequence of microfilm frames across any arbitrary sequence of microfilm frames by creating a chained sequence of links in the way just described, along with personal comments and side trails.

In 1965, Bush took part in the project INTREX of MIT, for developing technology for mechanization the processing of information for library use. In his 1967 essay titled "Memex Revisited", he pointed out that the development of the digital computer, the transistor, the video, and other similar devices had heightened the feasibility of such mechanization, but costs would delay its achievements.<ref>{{cite web|title=The MEMEX of Vannevar Bush|date=4 January 2021|url=http://history-computer.com/Internet/Dreamers/Bush.html|access-date=12 August 2023|archive-date=7 January 2021|archive-url=https://web.archive.org/web/20210107233415/https://history-computer.com/Internet/Dreamers/Bush.html|url-status=dead}}</ref>

===SMART===
Gerard Salton, who died on August 28 of 1995, was the father of modern search technology. His teams at Harvard and Cornell developed the SMART informational retrieval system. Salton's Magic Automatic Retriever of Text included important concepts like the [[vector space model]], [[inverse document frequency|Inverse Document Frequency]] (IDF), Term Frequency (TF), term discrimination values, and relevancy feedback mechanisms.

He authored a 56-page book called ''A Theory of Indexing'' which explained many of his tests, upon which search is still largely based.

===String Search Engines===
In 1987, an article was published detailing the development of a character string search engine (SSE) for rapid text retrieval on a double-metal 1.6-μm n-well CMOS solid-state circuit with 217,600 transistors lain out on a 8.62x12.76-mm die area. The SSE accommodated a novel string-search architecture which combines a 512-stage finite-state automaton (FSA) logic with a content addressable memory (CAM) to achieve an approximate string comparison of 80 million strings per second. The CAM cell consisted of four conventional static RAM (SRAM) cells and a read/write circuit. Concurrent comparison of 64 stored strings with variable length was achieved in 50 ns for an input text stream of 10 million characters/s, permitting performance despite the presence of single character errors in the form of character codes. Furthermore, the chip allowed nonanchor string search and variable-length `don't care' (VLDC) string search.<ref>{{cite journal|last=Yamada|first=H.|author2=Hirata, M. |author3=Nagai, H. |author4= Takahashi, K. |title=A high-speed string-search engine|journal=IEEE Journal of Solid-State Circuits|date=Oct 1987|volume=22|issue=5|pages=829–834|doi=10.1109/JSSC.1987.1052819|bibcode=1987IJSSC..22..829Y|publisher=IEEE}}</ref>
<!-- Potential source for article expansion:  http://ieeexplore.ieee.org/search/searchresult.jsp?queryText%3Dsearch-engine&sortType=asc_p_Publication_Year&pageNumber=1&resultAction=SORT -->