Page Monitors - Information Trapping: Real-Time Research on the Web - page 54

Figure 3.8
Changedetect's control
panel looks a little
cryptic until you get
used to it.
If you're using the fee-based version of the service, you also get the option
to use a user name and password (for monitored pages that require valida-
tion). And don't forget to check out the advanced options at the bottom of
the page. You can set the monitor to trigger when the page changes by a
certain number of bytes, when a word or phrase does (or doesn't!) appear,
or when one of a series of keywords appears. (here's a regular expression
content ilter, but it's available only for advanced users.)
ChangeDetect is available in three lavors: Personal (up to 10 pages moni-
tored, $1.95 a month), Plus (up to 100 pages monitored, $14.95 a month), or
Professional (up to 500 pages monitored, $39.95 a month). An enterprise
version is also available.
trackle
I use Trackle (trackle.com) and like it a lot for pages that I know will change
on a regular basis, and for pages for which I don't need anything but plain
text updates.
Trackle ofers a free 14-day trial available. Once you sign up (this requires
only a user name, password, and e-mail address), a one-page form displays
that allows you to enter a list of URLs (up to 25) and which hours of the day
you want to monitor them (up to 24, though once or twice is usually enough).
hen just click the Update/Activate button and you're set ( Figure 3.9 ).