Multiple monitors

Dual-monitor configuration

Experimentor supports computers with multiple monitors; when you choose to run a session in full-screen mode the full-screen subject-facing screen will automatically appear on the other monitor.  That is, if you are running the main Experimentor window on the primary monitor, then the full-screen subject screen will appear on the secondary monitor; however if you are running the Experimentor window on the secondary monitor then the full-screen subject screen will appear on the primary monitor.

Primary and secondary screens

Experimentor has the internal concept of a primary and a secondary screen.  The primary screen is the screen that the subject is viewing while they are running through a session, and is therefore the most important screen.  Thus, when Experimentor is running a session, any shapes’ percent values (for example, a shape’s X or Y locations, width, height, radius, etcetera specified as a percent) are converted into real or “absolute” co-ordinates using the dimensions of the primary screen.

When you run in non-full-screen mode, the primary screen is embedded inside the Experimentor application itself; thus, if you change the size of the window you can see shapes move or change size as their percent values are re-calculated against the primary screen’s new size.

When you run a session in full-screen mode, the full-screen view is the primary screen.


If you have a dual-monitor configuration, then when you run in full-screen mode the full-screen is the primary screen (against which percent values are resolved to absolute values) and the view inside the Experimentor application becomes a secondary screen.  This secondary screen behaves differently than the primary screen!   The secondary screen attempts to show you as closely as possible what the user is seeing on the primary screen, showing a “scaled down” version of the primary screen.  That is, the secondary screen takes the absolute values from the primary screen and scales them down to the secondary screen providing a decent approximation of what the actual subject is currently seeing.

More than three monitors

Experimentor also supports more than three monitors.  Like the dual-monitor configuration, when you run in full-screen mode Experimentor will automatically keep the Experimentor window on the current screen, and use the other monitors for the subject.  Here is a view of how that might be used with three monitors:


There are a few things to know about when running this type of configuration:

    1. The other monitors should be configured to be side-by-side in Windows.  Here is the Windows 7 Display configuration for a 3 monitor set-up:

In this example I’m running the Experimentor window on the left hand monitor (#3) and then when I run sessions in full-screen mode the full-screen window presented to the subject spans monitors #1 and #2.  I can also run Experimentor on the right-hand monitor (#2) and then the subject’s full-screen view spans monitors #3 and #1 quite nicely.  However, running Experimentor on monitor #1 and trying to get the subject’s session view to span #3 and #2 does not work.  

    1. The next important point is that the two monitors that you plan on displaying to the subject should be set to use the same screen dimensions.  Even with multiple monitors there is only a single session-view which is spanned across both monitors, so if one monitor has a different size then some of the subject’s session-view will not be visible on the smaller monitor.