Experiment Files: Key Concepts

The experiment editor allows to you to create, view and edit the details of your experimental conditions. The Experiment File you create using this editor is the first thing that MediaLab looks at when you go to run the experiment. You specify here which questionnaires, images, videos, sounds, documents, html files, executables or PowerPoint shows you want to present in each condition, and the order in which you want them presented. When you run the Experiment File, MediaLab will ask you which condition you want to run. It will read your Experiment File, determine which files you have specified for that condition, and then it will present those files to the subject in the order you have specified.

Think of the Experiment Files like a tabletop and the Questionnaire Files as a bunch of jigsaw puzzle pieces.  The Experiment Files serve as the surface upon which you arrange all of the individual pieces of your experiment--Questionnaire Files.  The Questionnaire Files serve the all-important purpose of where you organize the general order of elements of your experiment like the items and their presentation order.

With the exception of questionnaires, no data is gathered for files that you specify in Experiment Files. This is a very important concept. Data is only gathered in Questionnaire Files that you create. It is a good idea to give each of your Questionnaire files a test run to make sure that they run as intended and to check that the data files they produce are correct. Questionnaire Files are much more flexible in terms of the types of files and information that can be presented and the type of responses and data that can be collected.

The Experiment file that you create with the experiment editor simply tells MediaLab which files are to be presented in each of a virtually unlimited number of conditions. This can be as simple as assigning a single Questionnaire File to each condition, or as complicated as multiple questionnaire files assigned to each condition, each interspersed with video, audio, graphics, Word documents and PowerPoint shows for which data does not need to be gathered (e.g., for instruction screens or debriefing documents).

Remember though that all file types can also be presented in a Questionnaire File if you like. That is why the Experiment File can be as simple as stating which questionnaire (or set of questionnaires) is assigned to each condition. Additional files can be specified simply for the purpose of having this flexibility in the case that your application requires it.