The Internet is a large computer communication network that
spans hundreds of countries and includes millions of computers.
It is a heterogeneous network of networks, all communicating via
the TCP/IP communication protocol, that provides a number of
valuable services, including:
- WWW - The World-Wide-Web (WWW or just the web)
supports the sharing of hypermedia (i.e., text, video,
audio documents).
- Email - Electronic mail (email) supports the
semi-private exchange of messages.
- Other Internet-based communication services, including chat
and voice-over IP.
World-Wide-Web
Once you get connected to the Internet, the web is accessible
through a standard web-browser (e.g., Microsoft Internet
Explorer). You just need to tell the browser the Internet
address (or URL) of the page you want to download (see the
image to the right).
There are any number of useful websites, covering a vast
range of information resources, including:
The Web is so large and is growing so quickly that it’s
increasing difficult to keep track of it all. For this reason,
search engines have become a necessity. A search engine
allows you to enter search terms (e.g., “Calvin College”) and
will return a list of websites that may be relevant to those
terms. The most popular search engine these days is Google (http://www.google.com/):
Exercise 2.a.1: Use the WWW to find answers to the
following questions:
- What will the weather be like tomorrow?
- What is an average cost of electricity per kilowatt
hour?
- What is the energy cost of performing an average Google
search?
- Find a website with information about you (if you
can!).
Record your answers so that you can email them to the course
instructor at the end of the lab period.
To get help on the basics of Google search, visit the Google
help page (http://www.google.com/help/basics.html).
Do this even if you think you know Google well, I learned some
things when I looked through this help, and I use Google hundreds
of times per day.
Protecting Yourself on the Web
As in real life, not everything on the web is good, and some
sites can be dangerous. Here are some things to watch out for,
and some things you can do to protect yourselves and your families
on-line:
- Hoax Sites - Some sites present inaccurate or
even dangerous information.
- Malicious Sites - Some sites will try to
get you to send in money or give out personal information over the
Internet. Be wary of this. You can usually trust a site like
Ebay, so long as the URL is www.ebay.com, but don’t trust
just any site. Never give private information out (e.g., credit
card numbers, phone numbers, addresses), unless you trust the site
and they are using https, a secure protocol (e.g.,
https://signin.ebay.com/).
- Addictive Sites - Some web services can be
addictive (e.g., chat, gaming, pornography, gambling). Stay away
from those sites, and see that your children do as well. Leave
your computer in a public place in your house, and control
Internet access (e.g., using Google’s “safe
search” facility or a web filter like K9 (http://www.k9webprotection.com/).
- On-Line Bullies & Predators - Remember
that the web is public. Very little that you and kids post there
is truly private. Thus, you should remind your kids (and
yourself) to limit the amount of personal information posted on
Weblogs, chat rooms or social networking sites. You never really
know who you are talking to. If necessary, limit your time on
such sites and review the material posted there.
Exercise 2.a.2: Consider one of the following
websites:
Determine if your website is legitimate, questionable,
authoritative, foolish, despicable, etc. Record your answers so
that you can email them to the course instructor at the end of
the lab period.
It can be hard to tell if a site is legitimate or not, but you
some resources to answer these questions and determine the purpose
and legitimacy of these sites:
Electronic Mail
Electronic mail (Email ) is a service that allows you
create, send and reply to messages, world-wide, in an inexpensive
and convenient way. To use email, you need to have access to the
Internet (as discussed in the last session) and an email service
account. There are a number of companies that offer free email
service, including:
Exercise 2.a.3: If you don’t already have an
email account, set one up for yourself now by going to one of
the given companies and following their instructions. We’d
suggest using Gmail because it provides a good email
client. Here are some things to note:
- You will have to find a unique email ID.
The system will help you find one that no one else uses. Pick
one that you and your friends can remember.
- You will have to set a password. Choose
one that you can remember and that is complicated enough that
other people (or programs) won’t be able to guess. For
example, avoid obvious passwords like “joshua”, your first
name, or other dictionary words. And note that capitalized
letters (e.g. Blob ) are different from lower-case
letters (e.g., blob ).
Protecting Yourself on Email
As with all things on the Internet, Email is a very useful
tool, but carries with it dangers. Here are some things to look
out for and what you can do about them:
- Spam - Spam is unsolicited, bulk
email. To protect against this, use a spam filter
(provided by most email systems) and don’t reply to any
unwanted email or click on the links they provide. I also
keep a separate email account for on-line shopping and
other things, which redirects much of my spam.
- Hoaxes - You will frequently receive
messages from people you don’t know with stories and pleas
for various things. In general, don’t believe everything
you read. You can check out a range of hoaxes at Snopes (http://www.snopes.com/); for
example, search for "nigerian scam".
- Phishing - You may receive messages
telling you that you need to “verify” or
“re-enter” your personal information (e.g., ID numbers
or card numbers). Don’t reply to these phishing scams or
click on the links they provide.
- Flaming - Email is good for short notes,
sending documents to friends and for administration. It is not
the best means of communication for emotional or private
correspondence. Because you can’t actually see the other
person, email exchanges on emotional subjects can quickly descend
into flame wars.
You can find further information on all of these topics at
Wikipedia (http://www.wikipedia.org/).
Webfoot has a guide to writing effective email (http://webfoot.com/advice/email.top.html).
Exercise 2.a.4: Look through your email system and
find an example of a Spam or Phishing email. Record it so that
you can submit it to the course instructor at the end of the lab
period.
Other Internet Communication Services
There is a wide variety of Internet or web-based communication
applications out there.
Exercise 2.a.5: If there is time, try out one of the following
communication utilities:
There is no end in sight to the variety of Internet-based
communication applications.
Checking In
When you are finished with all the exercises, do the
following:
- Collect the answers you’ve recorded and submit them to
the course instructor through email.
- Demonstrate that you’ve installed and used one of the
other Internet applications.
- Shut down your machine by choosing
“Start”-“Turn Off Computer” and then
“Turn Off”.