This poster and accompanied paper shortly introduce the method for user-triggered usability testing. The method is for capturing user experiences which are critical to usability in real context of use. A dedicated device called “UXblackbox” has been implemented for a desktop computer environment. The device saves the time information on user-initiated triggers and captures the user interface context from the computer and records the critical events of use during the usability test session. This recording is analyzed by a usability expert in order to find usability issues. In the poster the method is illustrated in general and some related work is explained on using the method with practical considerations.