The best 9/11 research sites on all sides of the issue, of which this site offers a partial list, are "deep" sites. They have navigation bars with many topics, under each of which you may find many subtopics. You will probably wish to keep the main topic page open while you branch out to several subtopics, many of which you may also wish to keep open as you branch further.

For this reason, when doing web-based research on 9/11 evidence, it is advisable to use tabbed browsing rather than normal browsing. Most modern web browsers support tabbed browsing.

Note on examples used on this page -- This discussion will use Mozilla Firefox for Macintosh for its examples. The version used for the screen shots uses the Firefox appearance theme called Nautipolis. The Windows version of Firefox is structurally much the same -- the main differences in appearance will depend on the appearance theme used. Internet Explorer and Safari offer behavior and options similar enough to Firefox's that you probably won't have trouble making use of the information presented here. But if you're using Internet Explorer, I strongly recommend switching to Firefox, for security reasons if nothing else.

Briefly, the difference between the two methods of browsing is as follows:

• Regular browsing -- Moving from page 1 to page 2 causes page 2's content to replace page 1's content in the browser window. In order to re-access page 1, you have to use the Back button, and if you then go to, say, page 3, the content of page 2 is lost. This makes it difficult to follow the page hierarchies by which deep sites are organized.
• Tabbed browsing -- To move from page 1 to page 2, you ask to have page 2 "opened in a new tab." Now both pages' contents are shown in the browser window, which becomes like a three-ring binder, with index-tab-like tabs in the browser's tab toolbar, which lies just above the main content portion of the window. Each tab is labeled with the title of the page whose content it represents:
  
  
  

  To get back to page 1, you simply click on page 1's tab -- page 2's content is still available on the page 2 tab. If you now ask to open page 3 in a new tab, its content becomes available under a page 3 tab, while page 1 and page 2 are still accessible by clicking on their tabs. Thus, you can open a hierarchy of pages, and be able to go back and check earlier pages in the process for clarification or to go on to other branches.

You'll find the tab controls in the following places:

• Macs -- under the Tabs tab in the Preferences window, accessible from the File menu.
• Windows -- under the Tabs tab in the Options window, accessible from the Tools menu.

These are the choices I've found most useful:

The purpose of these settings, and my reasons for making the above choices, are as follows. You may have different priorities.

1. New pages should be opened in: a new window -- This covers what happens when you click on a link on a web page or in an email message. Tabs are essential for browsing through deep sites, and can be useful for other purposes, but the more of them there are in a window, the narrower the tabs and the harder it is to read the name of the page the tab represents. So I prefer to have casual clicks (not involved in a hierarchical search) open a new window, unless I make an explicit choice to open a particular link in a new tab.
   (XP Note: for users of XP with the task bar set to "stack up" multiple windows in one item on the task bar, it can be annoying trying to pick through the popup list of windows when you click on the browser's name in the task bar. You may find that use of tabs, which you can see all at once without the need of a menu, may be useful in some cases.)
2. Warn me when closing multiple tabs: yes -- Closing a window involves clicking the Close-window button -- the upper-left red-dot on a Mac, the upper-right "X" in Windows. When you do this for a window that has a number of tabs open in it, you lose all the tabs. That's fine if you're intending to close the window. But on a Mac, for instance, the Close-window button is quite close to the Back button, so it's easy to close a window accidentally while you're trying to go back. Or you may intend to close just one tab, but absent-mindedly close the window, instead -- especially in Windows, where X is used for both functions. To protect against this, the multiple-tab warning feature pops up a dialog box when you try to close such a window:
   
   

   Having to click Close tabs in that dialog box, on those rare occasions when you really DO want to close the window, is a small price to pay to protect yourself from a cardiac-threatening adrenaline surge that can occur when a window full of hard-found tabs evaporates before your eyes.

3. Warn me when opening multiple tabs might slow down Firefox: yes -- If you highlight a folder in your Bookmarks list, or right-click on a folder in your Bookmarks Toolbar, you get a menu like the following:
   
   

   If you were to chose Open all in tabs by accident, you might end up opening a LOT of tabs when you didn't mean to, and it could take quite a while for that process to finish. Setting this warning ensures that you won't do that by accident.

   However, Open all in tabs can be very useful. For example, in this course I use web pages for illustrative purposes or documenting particular points -- sometimes several windows, each with a lot of tabs. Setting this up from scratch before class could be laborious and time-consuming. If, instead, I set up a bookmark folder for each window, containing bookmarks for the respective tabs in that window, I can launch the whole class worth of web pages almost instantly by opening a window for each bookmark folder and doing an Open all in tabs on it.

4. Always show the tab bar: no -- This setting (the default) means that the tab bar doesn't appear if there are no tabs to display -- i.e., only one tab is open. This saves vertical space in non-tabbed windows.
5. When I open a link in a new tab, switch to it immediately: yes -- When you click on a link in a web page or email message, you are probably accustomed to seeing the content appear immediately. This setting guarantees the same will be true of newly-opened tabs. If you were to set this to no, choosing to open a link in a new tab would leave you looking at the same page you were just looking at. The new tab would have appeared up on the tab bar, and its content would be available, but you would have to actively click on that new tab to open it and see that content.

If you haven't changed the browser's default link-opening behavior -- i.e., open new pages in a new window (2a, above) -- the way to open a link in a new tab in the current window is to right-click on it (or, on a Mac with a one-button mouse, control-click on it). This kind of clicking in almost any situation on a Mac or Windows machine will produce a context menu, which gives you a list of choices of what you can do with the thing you've clicked on. In this case, you'll see something like this:

Just left-click on Open Link in New Tab and, if you've set the option to switch to a new tab immediately (2e, above), the tab and its new content will appear.

The more tabs you open in a single window, the more crowded they get. Eventually, the browser will start shoving them off the left or right end of the toolbar, at which points the ends will look something like this:

. . . . .

In this particular browser appearance-theme, the fact that the left arrow is blue and the right arrow is gray indicates that the extra tabs are off to the left. You click on the blue arrow to start bringing the tabs back from that side (and shoving them off the other side) so that you can get to the one you want.

However, this won't do you much good if the tabs are so narrow that you can't read the titles. The same holds true if, although they're fairly wide, the site starts all its titles with the site name, so the content title is not visible (as with 9/11 Resarch in the above example) To get around either of these problems, click on the icon with the down-arrow at the right end of the tab bar. This provides you with a vertical menu of the tabs' full titles. Just click the desired title:

If the visible portions of the tab titles are very different from one another, it's fairly easy to tell which tab you're on. But if they're similar or identical (as above), you can only tell which one you're on by knowing how the browser distinguishes the active tab from the rest. Different browsers -- and even different appearance themes used for a single browser -- have different ways of showing this. In these examples (the Nautipolis theme in Mac Firefox), the appearance distinction is very subtle -- white instead of light gray. However, the active tab will always show the Close button (X -- see next topic) even if it is crowded out of the other tabs:

Closing a tab is simple. Just click on the X at the right side of the tab. If there are only two tabs left, and you have set the option to not always show the tab bar (2d, above), closing one of the tabs will cause the tab bar to disappear, leaving a "normal," tab-less window.