Lecture 2b: Web
Searching and Downloading
What You Will Learn Today
- Find information on the web using addresses,
navigational features of web sites, and various
search tools and techniques.
- Download and view Internet files of different data
using browsers, FTP clients and archiving software.
- Links can be put on text, pictures, or buttons.
- Most web pages have some sort of navigation bar of text or picture
links on the left or at the top or bottom.
- Some Web sites (like this one) use frames to separate navigational
pages from content pages.
- Some Web pages have forms similar to paper fill-in forms that
include buttons, menus, lists, text boxes, check boxes, radio buttons, etc.
- Some sites have a site map or site outline which lists all
Ways to Find Information on the Web
- If you know a web site address you can type it in the address box
and go there directly.
- Many large web sites have their own local search engines to
search internal databases.
- Several tools quickly search multiple sites on the Internet:
- A subject guide or directory is a web site that organizes its
content hierarchically by subject (topics and subtopics).
- A search engine searches the web for one or more keywords you
type and displays a list of pages found.
- A meta-search site submits your search to more than one search
- Using a human search service, you can hire a real person to
perform your search for you.
- Specialized search sites allow you to search for specific content,
- people names/addresses/phone numbers, multimedia, software, maps,
library books, products, newsgroups, mailing lists
- Scholarly databases give access to abstracts and full text of
articles published in academic journals, newspapers and encyclopedias.
- Keyword searching finds documents containing the word or words you are
- Use more than one word to narrow the search if you get too many
- Use Boolean operators to refine
- word1 AND word2 finds only pages with both terms. (The default for most search engines is AND.)
- word1 OR word2 finds pages with either term.
- word1 NOT word2 finds pages with word1 but without word2.
- Use + to include a term in a search, - to exclude it (filter
out unrelated pages you don't want).
- +word1 +word2 -word3 finds pages with word1 and word2 but
- Use quotes to search for an exact phrase, e.g. "Uganda
- Wildcard searching allows specifying parts of words but not all
search engines allow it.
- Some search engines allow other search criteria such as file or
media type, file name, size, modification date, etc.
- Browsers have search settings or preferences to customize which
sites to search for what types of content.
- If you write a research paper and use a web page or site as a source, you
must acknowledge it just like you do a book.
- Resources can be cited using one of several style guides:
- American Psychological Association, Modern Language Association, Chicago
Manual of Style
- The citation format also depends on what is being referenced:
- individual work, part of a work, journal or newspaper article, other
types of online communication
File Formats and Extensions
- To download and open a file, it helps to know what kind of file it is.
- Files on the web include many types or formats.
- Common formats include text, picture, sound, movie, animation, archive, or
- The file format is generally indicated by its extension.
- An extension contains a dot and one or more characters, e.g. .htm or
.html. It follows the filename.
- Why do most extensions have three letters? Which extensions are primarily
used on certain operating systems?
Common File Formats and Extensions
- Documents: .htm or .html or .shtml (formatted hypertext), .txt
(plain text), .doc (Microsoft Word document), .pdf (Adobe Acrobat Portable
Document Format), .rtf (Rich Text Format)
- Image files: .gif (Graphics Interchange Format), .jpg or .jpeg
(Joint Photographic Experts Group), .png (Portable Network Graphics), .bmp
- Audio files: .wav, .au, .snd, .aiff, .ra or .ram (Real Audio), .mid
- Video files: .avi, .mov, .qt (QuickTime), .mpg or .mpeg (Motion Pictures
Experts Group), .rm
- Animation files: animated .gif (GIF89a), .swf (Shockwave Flash)
- Archives: .zip (WinZip), .sit (StuffIt), .gz or .tar.gz or .tgz (GNU Zip)
- Programs: .exe (executable), cgi-bin/ (Common Gateway Interface
Script), .asp (Active Server Pages), .php (Apache's Hypertext Preprocessor), .cfml
(ColdFusion), .pl (Perl)
- To download a link to any type of file or a picture, right-click on
- You can then choose to open in a new window, save, copy, print, or view
- If you click certain types of files, you are asked if you would like to
open or save the file.
- If you select save, you will be asked for a filename and folder where
the file will be saved.
- The time it takes to download is displayed and depends on several
- the size of the downloaded file (1 MB = 1,000 KB = 1,000,000
- the speed of the web server and your Internet connection (and
possibly your processor speed and memory)
- the location of the source file and the traffic on the
server and on the network between the source and destination
- Many freeware or public domain programs can be downloaded
and installed for free.
- You should pay for shareware if you continue using it after a
- After downloading, you normally install the program by
- To run a program if it does not appear in a menu or icon, type its full
path name in the shell or command prompt.
- An archive is a collection of files, usually compressed to
take less space.
- You may need special software to uncompress and extract
- Some archives are self-extracting; you extract files simply by
double-clicking the archive.
- Some programs are distributed in archives and need to be extracted before installing
- File Transfer Protocol (FTP) is both a protocol and a type
of software for transferring files.
- Most browsers in use today have built in FTP features, but separate FTP
client software packages also exist.
- Files are accessed from FTP servers much like web pages from web
servers, except the URL begins with ftp:// instead of http://.
- FTP sites are becoming less popular because web pages and programming
can provide equivalent or better service.
- FTP is often used by computer professionals for downloading
software and documentation.
- FTP can be used to upload (publish) a website you created to a
To Do After Class
- Read Hofstetter Part 4, Finding Things on the Internet (ch.
in Your Future module 8a:
the web, second half.
- Look at the
Internet Links page
provided by the UMU Library.
- Browse some of the sites listed in the books
and pages above.
- Locate and use search engines to perform each type of search.
- Download and view files of different types.