Anatomy of an Experiment


An E-Prime experiment is built using a number of different E-Objects - like building blocks. Each block contains information and performs functions

The Experiment Object: consists of global settings such as the name of the data file, and performs global functions such as hardware initialization

The SessionProc Object: The SessionProc object is the "container" for the experiment, and takes the form of a "time line", onto which experiment objects are placed, each of which performs some action

The List Object: A table that specifies the different experimental conditions, the stimuli that will be presented in the different conditions, and the trial procedures that will be performed, as well as the number of trials in each condition

The Procedure Object: specifies the sequence of other objects that perform the individual actions of the experiment

Trial-level objects: for presenting stimuli, recording responses, giving feedback, pausing between stimuli etc.

Blocks are arranged in a hierarchy, with objects lower in the hierarchy "nested" within higher-level objects.

A typical experiment:

Experiment Object

Between-subjects List Object

Session Procedure Object

Within-subjects List Object

Trial Procedure Object

Image/Text/Sound Stimulus Object

Wait Object

Feedback Object