User`s guide

E-Prime User’s Guide
Chapter 2: Using E-Studio
Page 53
2.7.3.3 Add the EndPrac object to the SessionProc
It is important to inform the subject whether they have met the accuracy criterion. We do this by
adding the EndPrac object to display the text determined by the preceding CheckAccuracy Inline
object.
Add a TextDisplay object to the SessionProc following the CheckAccuracy object. The text for
this object to display will be assigned at run-time via the CheckAccuracy InLine object, so no text
need be entered for this object. Set the Duration property for the EndPrac object to 3000
milliseconds. The EndPrac object is not necessary for the process of repeating the practice trials,
but helps to make the experiment execution more understandable to the subject.
2.8 Stage 6: Special Functions – Setting
Timing Modes, and Graceful Abort
Note: This section builds on the experiment created during the previous section. A finished version of Stage5-
LexicalDecision001.es is located in the C:\My Experiments\Tutorials\Using E-Studio Stages directory.
At this point there should basically be a functioning experiment. However, additional checks need
to be made to verify the timing precision and perhaps to structure the experiment to allow
experimenter termination of the experiment.
2.8.1 Checking timing modes
Chapter 3 – Critical Timing in the E-Prime User's Guide details methods to specify and check
timing. There are two primary timing modes that each object can use (more modes are detailed
in Chapter 3 – Critical Timing).
Event mode – maintain the duration for start to end of duration to be as specified. If there are
delays (e.g., due to waiting for the screen refresh), lengthen the inter-stimulus interval to
compensate for any delays.
Cumulative mode – maintain the duration from the start of one stimulus to the start of the next
stimulus to be the specified duration. If there are any delays (e.g., waiting for the screen refresh),
shorten the inter-stimulus interval so the second stimulus occurs at the requested time in relation
to the intended display of the first stimulus. This maintains the interstimulus interval.
In this experiment, the timing mode specified on the Duration/Input tab for all stimulus display
objects should use Event mode with a PreRelease of 0ms (which is the default). The following is