Chem 122 Laboratory, Spring 1996

Chemical Informatics: How to find it on the 'net

Note: this experiment may be done on any IBM-PC or Macintosh in any WAM lab or on any computer that has Netscape and access to the Internet. If you are unsure how to launch Netscape, ask the attendant.

A. Locating information on specific topics.

A good way to run a search for specific information on the Internet is to use a search engine, at network tool that automates the searching and retrieval process. Modern search engines can search World Wide Web pages, gopher items, and newsgroup articles. There are many such search engines; a good one is "AltaVista". To access it, launch Netscape, select Open Location... from the File menu, type in

http://www.altavista.digital.com/

and press RETURN. Set a bookmark to this page so you can return to it easily (Select Add Bookmark from the Bookmarks menu).

Like all search engines, AltaVista has a rectangular box where you type in one or more keywords that describe the topic or item you wish to find. You then click on the "submit" button. After a few seconds, the search engine will return the number of "hits" and a hit list giving the name, address, and short description of the information that it found. Each hit has a blue-colored underlined "hyperlink" to the on-line source of that information. If the item sounds useful, click on the hyperlink to go to that source. To return to the list of hits, click on the Back button at the top left of the Netscape window.

You can use any number of keywords to describe the information that you want more completely; the search engine will put at the top of the hit list those documents that contain all or most of the keywords and that use them most often.

In some cases you may need to search on a specific phrase (group of words) in a specific order. In that case you put the phrase in quotes in the keyword box. For example, say you need to find information about the topic of computer chemistry, which is the use of computers to simulate the behavior of molecules and reactions. Using the AltaVista search engine, type in the words computer and chemistry into the keyword box and run a search. How many hits do you get? ____________. Look at the first couple of hits. Do they mention computer chemistry? _______ . You got all those hits because the words "computer" and "chemistry" occur very commonly in the same document but in separate places. Now run a search on the phrase "computer chemistry" (including the quotes). How many hits do you get now? _________. How are these hits different from the results of the first search?

________________________________________________________

B. Evaluating the information that you find.

So you have found a site or document that seems to be useful? How reliable is that information likely to be? Just because it's on the 'net does not mean it's correct or reliable. It helps to know who wrote or created that information and what institution they represent. If no one is willing to put their name to the document, it arouses suspicion. On the other hand, if an official government agency or accredited education institution publishes information and clearly labels it as an official publication, then it is likely to be more reliable.

The ideal situation is when a document carries an author, affiliation, and a date. For example, go to http://www.wam.umd.edu/~toh/NetscapeHandout.html.This page is clearly labeled. Moreover, it contains, at the bottom, hyperlinks to the author's personal home page, to his email address, and to the "mother" document (the document in the next higher level of the organizational structure of related documents, which in this case turns out to be a list of similar tutorial handouts).

In contrast, go to http://alpha.acast.nova.edu/nova/tutor/lesson_plans.html. I came across this page in running a search for "lesson plans". You can see why the search engine hit on this page, but you can't tell anything about who created it or when, or who they work for. It's clear that this is an educational site (from the ".edu" in the address), but what the heck is "nova"? No clue.

What can you do in that case? There is a trick that you can do to learn something about the source of the information in such cases. It is based on the structure of the address: each segment of the address separated by a slash (/) represents a directory in the file system of the host computer (the same as the nested folders on Macintosh and Windows computers). The idea is to "move up" the directory structure, by sequentially deleting each segment of the address, starting with the last (right-most) segment. For example:

1. Go up to the Location field at the top of the Netscape window (if there is none, select Show Location from the Options menu).

2. Edit the address there by selecting and deleting the last part of the address (lesson_plans.html). That is, drag the mouse over lesson_plans.html and press the delete key. This leaves http://alpha.acast.nova.edu/nova/tutor/ in the location field.

3. Press the RETURN key. This activates the truncated address, which will take you either to the "index" page for that directory or a listing of files in that directory (including the document you were just viewing). In this case it leads to the home page of the author of the lesson plans page. What is the author's name? __________________________.

4. Keep on deleting the next segment of the address. When you get to http://alpha.acast.nova.edu/, you have arrived at the "root" directory, from which you can usually tell something about the host organization. What is the name of the host organization in this case? _______________________

______________________________________________________.

C. Search Assignment. Search for the requested information or answer to the questions posed. When you have found a suitable site (Web page, etc.), write down the name of the search engine you employed, the keywords you used, the address of the best page you found that contains that information, the author of the page (if given), and the organization (institution or company) that the author represents.

1. What is a "spectrophotometer" and what is it used for?

Keywords used: _________________________________________

Title of page: _________________________________________

Address of page: _________________________________________

Author(s): _________________________________________

Institution: _________________________________________

Answer to the question:

______________________________________________________

2. What is a common use for the compound "calcium propionate"?

Keywords used: _________________________________________

Title of page: _________________________________________

Address of page: _________________________________________

Author(s): _________________________________________

Institution: _________________________________________

Answer to the question:

______________________________________________________

3. I have heard that there is a K-12 curriculum development project based somewhere in New York called "MathMol" that connects chemistry and mathematics. Find out if they have a Web page and describe the major goals of this project.

Keywords used: _________________________________________

Title of page: _________________________________________

Address of page: _________________________________________

Author(s): _________________________________________

Institution: _________________________________________

What are the major goals of this project?

______________________________________________________

4. I'm looking for a general source of information about the nutritional content of various foods (e.g. how much protein, fat, iron, calcium, etc). Find me an on-line source that has lots of good information on this topic.

Keywords used: _________________________________________

Title of page: _________________________________________

Address of page: _________________________________________

Author(s): _________________________________________

Institution: _________________________________________

What makes this site a useful source?

______________________________________________________

5. Any time you buy a manufactured chemical, it comes with a document called a "Material Safety Data Sheet", that gives safety information (toxicity, handling precautions, etc). Is there a freely accessible on-line source of Material Safety Data Sheets for various compounds?

Keywords used: _________________________________________

Title of page: _________________________________________

Address of page: _________________________________________

Author(s): _________________________________________

Institution: _________________________________________

How are the Material Safety Data Sheets organized?

______________________________________________________

6. I heard that "lithium" is used as a psychotropic drug. Find out (a) what disorder it is used to treat; (b) what chemical form is used; (c) what is the typical therapeutic dose; and (d) how does the therapeutic dose compare to the toxicity limits for humans specified in the Material Safety Data Sheet for the dosage compound.

Keywords used: _________________________________________

Title of page: _________________________________________

Address of page: _________________________________________

Author(s): _________________________________________

Institution: _________________________________________

a)_____________________________________________________

b)_____________________________________________________

c)_____________________________________________________

d)_____________________________________________________

______________________________________________________

7. I'm interested in the relationship of the smell (odor) of chemical compounds and their molecular structure. See if you can find a database that lists a number of smelly compounds, describes their smell and natural occurrence, and gives the molecular structures (preferably with pictures of molecular models).

Keywords used: _________________________________________

Title of page: _________________________________________

Address of page: _________________________________________

Author(s): _________________________________________

Institution: _________________________________________

How did you locate the home (top) page of this database?

______________________________________________________

8. Someone told me that there is a "chemist's art gallery" on the World Wide Web that originates in Finland. Find it.

Keywords used: _________________________________________

Title of page: _________________________________________

Address of page: _________________________________________

Author(s): _________________________________________

Institution: _________________________________________

What kind of "art" do they have there?

______________________________________________________

Go to Chem 121 Home Page

This page is maintained by Prof. T.C. O'Haver, Department of Chemistry and Biochemistry. Comments, suggestions and questions should be directed to Prof. O'Haver at to2@umail.umd.edu.

Created Mar. 4, 1996.