Relevance ranking: Ranks according to how many of your search terms a page contains, where in the document, and how close to one another the search terms are.
Results presented as: First several lines of document.  "Detailed" summaries don't appear any more detailed than "standard" ones.
User interface: Like the other search sites, AltaVista has turned to the "directory" or "portal" page cluttered approach.  We miss the old, clean interface!
Help files: Complete, and clearer than they used to be.
Good points: Fast searches, capitalization and proper nouns recognized, largest database; finds things others don't.  Alta Vista searches both the Web and Usenet.  It will search on both words and on phrases, including names and titles. You can even search to discover how many people have linked their site to yours.   You can also have the resulting pages of your searches translated into several other languages.
Bad points: Multiple pages from the same site show up too frequently; some curious relevancy rankings, especially on Simple search. Old, outdated pages stay in the index for too long.
Overall Rating: B+

Excite
Excite uses concept-based indexing, although it no longer brags about this or goes out of its way to explain it.   But Excite uses statistical methods to try to determine what a particular web page is about.  Also looks at link popularity.

Type of search:  Concept-oriented; also uses keywords.
Search options:  Simple, Advanced, allows Booleans and phrase (adjacency) searching.
Domains searched:  Web, News, Pictures, MP3s and classified ads
Search refining:  Suggests you use more words, repeating key choices several times. Uses a fuzzy AND, which searches AND and OR, giving preference to AND.  Has recently added Boolean operators to aid in search refining--AND, OR, AND NOT, and the characters + and -.
Results returned in:  Summaries, which seem to be taken from the "description" Meta tags. 
User interface:  Generally good, nothing exciting.
Help files:  Used to be much better than they are now.
Good points:  Large index. Not quite as up-to-date as it used to be. Excellent summaries, which they admit are actually highlights--the top few most important sentences in the document. Bad points:  Does not specify the format or the size in megabytes of the hits it returns.
Overall rating: B+

Fast (alltheweb.com)
FAST is one of the newer search engines, and it claims to be the biggest, fastest and most scalable.  It seems to be living up to those claims quite well, and FAST's technology has been adopted by Lycos as their main search engine on their website.

Type of Search:  Keyword
Search Options:   Simple, Advanced
Domains Searched:  Web, mobile web, FTP files, multimedia, MP3s, will search many foreign languages.
Search Refining:  Full Boolean, phrases. Pull down box choices allow you to search easily for all the words (Boolean AND), any of the words (Boolean OR) or the phrase.
Good Points: A clean, uncluttered interface -- a good point FAST search shares with Google.
Overall Ranking:  A

Go - Formerly Infoseek
Infoseek, one of our favourite search engines of the second half of the 1990s, has been dismantled by Go (i.e. the Disney site), which took it over.  It's no longer on the site at all.  They're now using GoTo's search engine, which includes paid listings, and also uses search technology from Inktomi.

Google
Type of search: Keyword.   Default for multiple keywords is Boolean "AND."
Search Options:  Basic or Advanced
Domains searched: Web, news, stock quotes, special searches on Government documents.  Now indexes PDF documents, too.
Search Refining: Full Boolean
Relevance Ranking:  Google ranks in part according to how many links a web document has from other websites, and it also looks at the quality of the referring websites.  Google uses this method to refer Google searchers to what it considers the best documents on the web.
Interface:  Clean and simple -- a simple query-entry field and search button.  Google is one of the only search engines to resist cluttering up the page with other distracting material.
Good Points:  Excellent, highly relevant results.   Google has quickly become a favourite among searchers, and is now used to power Yahoo's web search, too.
Overall Ranking: A

Lycos (Now uses the FAST engine)
Type of search: Keyword, but Lycos is now less of a search engine, it seems, and more of a Yahoo-like subject index.  Has recently had a cool graphical facelift. Proud of its ability to search on image and sound files.
Search options: Basic or Advanced
Domains searched: Web, News, Stocks, Jobs, Weather, and Multi-media.
Search refining: Lycos now has full Boolean capabilities
Relevance ranking: Lycos no longer provides a relevancy ranking.
Results presented as: First 100 or so words in simple search, you choose in advanced search--summary, full results or short version.
User interface: Clean, clear, focuses more on directory now than on simple search.
Help files: Good, informative, graphical help screens are easy to understand.
Good points: Large database.  Comprehensive results given--i.e., the date of the document, its size, etc.  Lycos indexes the frequency with which documents are linked to by other documents to make sure the most popular web sites are found and indexed before the less popular ones.
Overall Rating:  B+

HotBot (Now allied with Lycos) Uses search technology from Direct Hit and Inktomi
Type of search: Keyword
Search options: Simple, Modified, and Expert
Domains searched: Web
Search refining: Multiple types, including by phrase, person and Boolean-like choices in pull-down boxes. No proximal operators at present. In Expert searches you can search by date and even by different media types (Java, JavaScript, Shockwave, VRML, etc.).
Relevance ranking: Yes.  Methods used--search terms in the title will be ranked higher search terms in the text. Frequency also counts, and will result in higher rankings when search terms appears more frequently in short documents than when they appear frequently in very long documents. (This sounds sensible and useful).
Results presented as: Relevancy score and URL
User interface: Very cool and lively. Some users have complained about the bright green background, but we like it.
Help files: A FAQ that answers users' questions, but not a lot of serious help files.
Good points: Claims to be fast because of the use of parallel processing, which distributes the load of queries as well as the database over several work stations.
Bad points: Some limitations still on Boolean operators, and the help files still aren't very good.
Overall Rating: B

Yahoo
Although not precisely a search engine site, Yahoo is an important Web resource.  It works as an hierarchical subject index, allowing you to drill down from the general to the specific.  Yahoo is an attempt to organize and catalogue the Web.
Yahoo also has search capabilities.  You can search the Yahoo index (note: when you do this you are not searching the entire Web).  If your query gets no hits in this manner, Yahoo offers you the option of searching the Google engine, which does search the entire Web.
Yahoo will also automatically feed your query into the other major search engine sites if you so desire.  Thus, Yahoo has the capacity to act as a kind of meta-search engine.

Type of search:  Keyword
Search options:  Simple, Advanced
Domains searched: Yahoo's index, Usenet, E-mail addresses.  Yahoo searches titles, URLs and the brief comments or descriptions of the Web sites Yahoo indexes.
Search refining:  Boolean AND and OR.  Yahoo is case insensitive.
Relevance ranking:  Since Yahoo returns relatively few hits (it will never return more than 100), it's not clear how results are ranked.
Results presented as:  Yahoo tells you the category where a hit is found, then gives you a two-line description of the site.
User interface:  Excellent, easy-to-use
Help files:  Not very complete, but since there aren't a lot of search options, detailed help files are not necessary.
Good points:  Easy-to-navigate subject catalogue.  If you know what you want to find, Yahoo should be your first stop on the Web.
Bad points:   Only Yahoo has actually catalogued a small portion of the Web.
Overall rating: A (This rating refers simply to Yahoo's quality as a directory-searches of the entire Web are not possible).