The FAQ

1. What is W3QS?

W3QS - The WWW Query system, is a system for searching and extracting information from the WWW.

2. What is a query?

A query is a declarative description of a search. For example: "Go to the home page of www.tralala.com, gather all the images in the site accessible by navigating up to depth 5" is a query. In W3QS, a user can define queries and have them executed even if he/she is not connected during the actual search. At any time, the user can reconnect to the site of W3QS and verify if the queries are complete. It is also possible to request W3QS to send email when a query completes. A user can also request to have query results automatically refreshed at pre-determined intervals. 

3. Why use W3QS?

W3QS has features that are usually not available in standard search engines:

  1. W3QS executes its searches on the WWW in its current state. Other search engines use indexes (databases) containing extracted WWW data. Since the WWW is very large and rapidly changing, this index  is not always accurate. If you search for information in  a site whose content changes frequently, you cannot trust standard search engines. So, W3QS searches take more time but reflect the actual content of the WWW.
  2. W3QS searches are more precise than the searches that use standard search engines. Search engines usually allow searches based on keywords. In W3QS, you specify your searches by defining how to navigate to the information of interest. Therefore, you can define searches in a more precise way. For example, you can extract all the images from a site or find all the pages in a site that contain some string...
  3. W3QS can navigate in sites that use forms. If you search a site that requires the user to fill some online forms, W3QS can handle the task. The first time it encounters a form our search engine will request you to fill it out and will record your input. The next time this form is encountered, our search engine will fill it automatically.
  4. W3QS searches even when you are not "connected". Each user has an account in which his/her queries are saved. So you can define a search, send it to execution and come back tomorrow to see its results.
  5. W3QS can use other search engines. In W3QS, you can define a search that says: "Go to these standard search engines, query them about xxx and continue the search from the addresses they supply".
4. What is W3QL?

Queries in W3QS are translated into a computer language called W3QL. However you do not need to learn this language to use W3QS. You can define searches simply by filling our search form. The content of the form will be automatically translated to W3QL and sent for execution. Expert users can write queries directly in W3QL. More information on W3QL is availlable   here.

5. I sent a query called XXX, and when I look at my queries list I see several queries called: XXX_Part_1, XXX_Part_2, XXX_Part_3..., What are these queries?

When you specified a query XXX, you defined the information to be searched for (for example: images). When this query is translated into W3QL, several sub-queries are generated. XXX_Part_1 searches for the information you requested in the sites'home pages, XXX_Part_2 searches for the information in pages accessible from these home pages etc... Therefore, you can look at the results of a part of your query before the whole query completes. When you press on the COLLECT button adjacent to near the query name, the results of all the parts of your query that have completed are gathered.

6. What is the meaning of the buttons next to a query's name?

When you look at the list of your queries, you see four buttons next to the query name:
EDIT is used to edit the W3QL code of the query or simply to change the name of the query and re-send it to execution.
DELETE is used to delete a query.
MESSAGE is used to view the messages generated by our search engines during the search. Therefore, you can monitor search execution, and obtain information during the execution of the search.
RESULTS is used to view the results of your query.

7. What is the meaning of a blinking light next to a query's name?

A blinking light  next to a query name means that our search engine encountered a form during the execution of the search and it waits for your input. You should click on the light to continue, fill out the form and then the query execution will resume.

8. How do I use a result table?

A result table looks like this:
 
Page1 PROJECT
 link 1 Page 2 PROJECT link2 Page 3 PROJECT
index.html <a href="toto.html"> toto.html <img src="toto.gif"> toto.gif
... ... ... ... ...

Each row in the table describes a navigation done by our search engine. For example, the first row of the table above means that our search engine started at a page called index.html, followed a link to a page called toto.html and found there an image called toto.gif (the information you searched for). By pressing on the PROJECT button you can view the content of just one column.

9. Where can I find more information on W3QS?

Right   here.

10. Who wrote W3QS?

W3QS have been designed by  David Konopnicki  and  Oded Shmueli.

11. Do I have to pay for W3QS services?

W3QS services are free!!

What determines W3QS response time

W3QS runs on a server located at the Technion, Haifa Israel. Network speed may affect response time. Query compilation is usually very fast. It may be slowed down if many users are concurently active. Search execution is affected by the query complexity, network speed and users load on our server.

12. Activate W3QS?
It's here!