Internet

Today’s Internet – Very different from yesterday’s

Very different from tomorrow’s

What is the Internet?

The Internet is a constellation of communicating devices supported by a common communications protocol (TCP/IP), offering these capabilities/ (applications):

SMTP – Simple Mail Transport Protocol (aka “Email”)

telnet -- the ability to connect to a remote host and interact as if one where onsite

FTP – File Transfer Protocol, the ability to connect to a remote host and upload/download a file

Internet History Milestones

Early discoveries -- ARPANET networks & Telnet & TCP/IP (1983)

FTP -- file transfer protocol--Archie Gopher -- 1991 -- menu client --don’t

forget Veronica & Jughead (sample)

WWW-- 1993 added graphics & media--moved from classroom to boardroom

Internet 2 -- 1996 -- new possibilities—Now you see Web 2.0 (or Lib 2.0)

Sample Gopher Menu--Information About Gopher

(FILE) About Gopher (?) Search Gopher News> (DIR) Gopher News Archive (DIR) Gopher Software Distribution (DIR) Commercial Gopher Software (DIR) Gopher Protocol Information(FILE) University of Minnesota Gopher software licensing policy(FILE) Frequently Asked Questions (DIR) comp.infosystems.gopher (USENET newsgroup)(FILE) Adding Information to Gopher Hotel (MOV) Gopher T shirt on MTV movie (big) (MOV) Gopher T shirt on MTV movie (small) (IMG) Gopher T-shirt on MTV #1 (IMG) Gopher T-shirt on MTV #2

The World Wide Web is

A software application, most often running on the Internet (but not required to be) using a client – server protocol for communications.

What makes the Web Unique?Hyperlinks !!!

Hyperlinks (the ability to move from one source to another in a webbed environment) are the primary reason why the Web is so popular (and navigable).

Hyperlinks are examples of “associative trails” (Vannevar Bush

1945)

So what is “client-server”?

Client-server itself is a software application that supports connectivity and functionality between users (running “client software applications”) and hosts, or servers running server-side software.

Sometimes we call this design philosophy an “Open Systems” design, since it supports multiple H/S platforms.

Top Level Domains

Original TLDs - .edu, .gov, .com, .mil, .net, .org, .us

New TLDs - .aero, .biz, .coop, .info, .musuem, .name, & .pro

Hostnames and the Domain Name Server (DNS)

Every host (aka system or computer) on the Internet requires a unique identification number, a numeric address

The Internet requires this number to get data from a source to a destination address

The number is built up of 4 numbers, each between 0 and 255 (aka, 4 bytes total)

For every hostname, such as sislt.missouri.edu, there is a numeric equivalent (128.206.171.229).

Hostnames and the DNS

We don't need to know an IP address for a particular hostname, or need to worry about how the data get from one place to another.

Experts, though, need to get behind the scenes to diagnose problems or errors.

Some utilities available include ping, traceroute, nslookup and whois. These are available for Unix/Linux and Windows machines, among others. (check out www.internic.com and dnsstuff.com)

Internet Protocols:TCP and IP

Protocols are rules for communication. By agreeing on such rules, the Internet works.

Many protocols are used for the Internet to make sure data get from one place to another. For example, the HyperText Transport Protocol (HTTP) governs how Web clients (browsers) talk with Web servers.

The defining protocol for the Internet is the TCP/IP protocol.

Internet Protocol

The Internet is the network of IP networks. TCP/IP—transmission protocol IP (Internet protocol) is a protocol that

manages getting data packets from one place to the other on the Internet regardless of hardware and software. The IP doesn't do any quality control or error handling, other than to make sure the payload arrives intact.

TCP (transmission control protocol) does quality control, packet reassembly, and other things to make sure the data are usable.

Important Internet Websites

http://www.w3.org World Wide Web Consortium

http://www.isoc.org Internet Society

How you (& others) use Internet

http://www.pewinternet.org/ PEW

http://www.clir.org/pubs/reports Council on Library and Information

Resources

Information Overload

“The greatest problem of today is how to

teach people to ignore the irrelevant,

how to refuse to know things, before

they are suffocated. For too many facts

are as bad as none at all.”

(W. H. Auden)

Information Hierarchy

WisdomKnowledgeInformation

Data

Information Hierarchy

Data Raw material of information

Information Data organized & presented by someone

Knowledge Information read/hear/seen AND understood

Wisdom Distilled & integrated knowledge AND

understanding

Information Retrieval Issues

Help users retrieve information relevant to their information needs--esp. in a Web world Find techniques that allow higher quality retrieval--

text, image, sound

Faster access Find techniques to improve indexing & efficiency

Understanding of user behavior Find better ways to design & deploy IR systems

and strategies

Effective Information Retrieval

Understanding the documents & data How to structure, store and retrieve Roles of good indexing, keywords, full-

text Automatic (crawl) and human

intervention retrievalStandards

Effective Information Retrieval

Understanding the vocabulary--relevant, precise, stemming (your vocab list)

Boolean searching http://lib.colostate.edu/tutorials/booleanadv_info.html

More Boolean Nesting & Proximity Operators--Adjacent, Near

Sometimes +, -, or “” better (implied Boolean)

Don’t forget the user is NOT you

Let’s Practice

Go to Blackboard Review Electronic ResourceSampleOn your own