Knowledge Base

Introduction

About This Technical Note

In this Technical Note you find all information you need to establish communication between The Observer XT and the E-Prime software for stimulus presentation, run a test and analyze the data of E-Prime and The Observer XT as one data set.

Throughout this note we assume that you are familiar with the basic use of The Observer XT and E-Prime Professional 3.0, and that you have created an E-Prime experiment in E-Studio.

After reading this note you will be able to:

• Set up The Observer XT and E-Prime to communicate with each other.
• Start recording in E-Run through The Observer XT.
• Automatically import the E-Prime data into The Observer XT.
• Analyze the E-Prime data in The Observer XT.

You can find this technical note in PDF format in the folder C:\Program Files (x86)\Noldus\EPrime Server.

Note: The Observer XT 14.1 and later versions combined with E-Prime Client/Server 1.5 and later were not tested with E-Prime 2.x. If you have E-Prime 2.0, make sure that this combination works before running an experiment.

For more information on The Observer XT, see The Observer XT Help. To open the Help, press F1 in the program. For E-Prime, see the E-Prime Reference Manual.

The Observer XT and E-Prime: Workflow

The workflow is generally as follows:

1. Make sure that the Observer XT and the E-Prime computers are connected to the local network.
2. In The Observer XT, open the project you require.
3. In E-Studio, open the E-Studio experiment that you require.
4. Prepare the test subject in front of the test monitor.
5. In The Observer XT, start an observation. This will send a start command to E-Run.
6. Let the E-Prime experiment run as usual.
7. When the E-Studio experiment has terminated, in The Observer XT stop the observation. The E-Prime experiment events are imported automatically into The Observer XT.

Prerequisites

Tools You Need

In order for The Observer XT and E-Prime to communicate, you need additional software installed on your computers:

• Noldus E-Prime Client 1.6. Installed on the computer where The Observer XT is installed.
• Noldus E-Prime Server 1.5. Installed on the computer where E-Studio is installed.

Noldus E-Prime Server also includes this technical note as documentation. You can find this technical note in PDF format in the folder C:\Program Files (x86)\Noldus\EPrime Server.

Note: If you have E-Prime 3.0 and The Observer XT 14.0, update The Observer XT to 14.1 or later version. The Observer XT 14.0 only works with older versions of E-Prime Server and E-Prime Client made for E-Prime 2.x.

Computer Connection

The Observer XT and E-Prime must be installed on two separate computers, connected through a Local Area Network (LAN). Make sure that your connection is stable. If connection is lost once during an observation, it cannot be restored and most likely the data of that observation will be incomplete or invalid.

The Noldus E-Prime plug-in 1.5 was developed with The Observer XT 14.1, E-Prime 3.0.3.31 and E-Studio Professional version 3.0.3.18.

E-Prime Add-on License

Your copy of The Observer XT can only work together with E-Prime if your Observer XT license includes the E-Prime Tool.

Operating System

The Noldus E-Prime Client and E-Prime Server software supports the 64 bit Professional editions of Microsoft Windows 10.

In Case of Complex Setups

When The Observer XT and E-Prime are part of a more complex observational setup, including for example a physiological data acquisition system which uses a dedicated board on the E-Prime PC, or IP cameras, make sure that The Observer XT communicates directly with the E-Prime PC, using either a crossover cable or a dedicated network switch.

If you use a network switch to connect The Observer XT and the E-Prime computers, it must have a fixed IP address with a range different from that of other switches, in order to prevent communication conflicts. For example: 192.168.0.101 for switch 1 and 192.168.1.xxx for switch 2.

Install the Software

The E-Prime integration solution consists of two pieces of software:

• The E-Prime Client software, to be installed on the computer where The Observer XT is installed.
• The E-Prime Server software, to be installed on the E-Prime computer.

On the Observer XT PC

1. Copy the file E-Prime Client 1.6 Setup.exe to The Observer XT computer.
2. Double-click this file and follow the instructions on your screen to install the E-Prime Client. Accept the terms in the License Agreement. The software is installed on C:\Program Files\Common Files\Noldus\The Observer\EPrime Client 1.

Proceed with the next section.

On the E-Prime PC

1. Copy the file E-PrimeServer 1.5 Setup.exe to the E-Prime computer.
2. Double-click this file and follow the instructions on your screen to install the E-Prime Server. Accept the terms in the License Agreement. The software is installed on C:\Program Files (x86)\Noldus\EPrime Server.

Proceed with the next section.

Set Up Communication

The Observer XT PC

1. In The Observer XT, create a new project or open an existing one.
2. Click Setup Project in the main window. Under Observation Source, select Live Observation.
3. If the Devices window does not open, click Devices under Live Observation.
4. In the Devices window, select the option E-Prime, and double-click the cell under Status.
5. In the new window that appears, next to E-Prime computer enter the IP address of the E-Prime computer. Leave the Port value as 155.

To obtain the IP address of the E-Prime computer: On the E-Prime computer, start the Noldus E-Prime Server, then click the Advanced settings tab. The window that appears contains the E-Prime Controller IP address.

6. Click OK, then OK in the Devices window.
7. Proceed with the settings on the E-Prime PC (next section).

Notes:

• You can also use a port number other than the default 155, but you must set it in both The Observer XT and in E-Prime Controller.
• If the E-Prime item does not appear in the Devices window, check that the E-Prime Client software is installed and that your license includes the E-Prime add-on.
• Some firewalls can block communication ports. If port 155 is blocked, ask your system administrator to find a free port that is not blocked. Select this new port number in step 5 above and in the Advanced settings of the E-Prime Server. Alternatively, let your system administrator create an exception in Windows Firewall for port 155.

The E-Prime PC

1. On the E-Prime PC, start Noldus EPrime Server.
2. On the Experiment Settings tab, browse to the experiment file you want to use (*.ebs3).
3. Click Start to activate Noldus E-Prime Server. From this moment on, it will accept messages from The Observer XT.

Notes:

• For E-Prime 2.0, the file extension is ebs2. Note: E-Prime 2.0 was not tested with The Observer XT 14.1 and later versions.
• Notice the difference between the file extensions: .es3 is the extension of E-Studio files, which specify the experimental procedure. The extension .ebs3 is of the E-Basic script file generated for that experiment. In order to have an ebs3 file in your experiment folder, generate it in E-Studio: choose E-Run > Generate. The experiment folder now also contains the ebs3 file.
• E-Prime Server can only be started once. If you start it multiple times, the Noldus E-Prime Server window comes on top of your screen.
• Do not click Exit until you are done with data recording. Instead, click the Minimize button or the Close (X) button.

Prepare the Experiment in E-Studio

Specify the Events to Import

A typical E-Prime experiment consists of a number of E-objects (instructions, stimuli, feedbacks) organized in nested sequences called procedures. Follow this section to specify the E-objects that you want to import in The Observer XT, and their properties.

1. Start E-Studio and open your experiment.
2. In the Experiment Explorer window, double-click one of the E-objects in your procedure.
3. In the window that appears, click the Properties button (this is located just under the window's title bar).
4. Click the Logging tab. Follow all steps below.

Default parameters

5. Make sure that OnsetTime and Duration are selected. System events like the presentation of a stimulus will be imported in The Observer XT as state events for the subject System using these properties.

Properties for User responses

6. For experiments in which a response is given by the test participant after presentation of a stimulus, make sure that the following items are selected:
   • CRESP (Correct Response)
   • RESP (Actual Response)
   • RTTime (Subject response timestamp)
   The participant responses will be imported in The Observer XT as point events for the subject "User".
7. Click OK.

Repeat steps 2 to 7 for all the other objects you are interested in.

Display Settings: E-Prime Experiments in Windows 10

Windows 10 only supports 32 bit color depth. However, when an E-Prime experiment that was created in a prior version of E-Prime and with a bit depth lower than 32 is loaded into E-Prime 3.0, E-Prime keeps the originally-specified color depth setting. This may affect the correct functioning of E-Prime.

To check that the Color bit depth is correct:

1. In E-Studio, choose Edit > Experiment (Ctrl+E).
2. Click the Devices tab, then double-click Display.
3. Next to Color Bit Depth, select 32 if not selected already.

Important: You must follow this procedure for any experiment that you open on that computer.

For a more general solution for Windows 8 and 10 computers, see the web page: https://support.pstnet.com/hc/en-us/articles/115001493487-INFO-Windows-8-DirectX-11-or-greater-detected-23888-

Specify the Event Properties to Import

For some events you may want to import additional information to The Observer XT, like the name of the picture used as a stimulus. This information can be imported as modifiers.

General rule: The Observer XT imports the object property that, in the Trial List, has the same name as the object. The values in the column cells are imported as modifiers.

In the example below, the object in the procedure is named Stimulus. Of this object, The Observer XT imports the values in the column Stimulus of the Trial List, RedCar.bmp and BlueCar.bmp. They are imported as modifiers of the behavior Show Stimulus.

Example 1: To Import Stimulus File Names

An image E-object has been inserted in a procedure, and named Prime. The trial list specifies that for Prime an image will be chosen randomly between the available image files, and displayed on the test participant monitor. The researcher requires that, for each instance of image presentation, the image file name is imported in The Observer XT as a modifier of the event "Show Prime". For example, "Show Prime - Flower_12.bmp".

1. Open the experiment in E-Studio.
2. In the Experiment Explorer window, double-click the list in which the object is located.
3. In the list properties window, click the Add attribute button. Enter the name as the object (in this example, Prime).
4. Fill in the cells in the new column with the names you want to import (in this example, the name of the image files for Prime).
5. In the Experiment Explorer window, click the E-object again.
6. Important: If the attribute value is a file (image, video, etc):
   1. In the Properties window locate the Filename item. In the field next to it, click the Browse button and select the folder that contains the stimulus files, then click OK.
   2. In the field next to Filename, type in the object name in brackets [ ]. In this example: [Prime].
7. Run the experiment in E-Studio (E-Run > Run or F7).
8. The experiment is ready to work with The Observer XT. The value of the attribute in a specific trial will be imported as a behavior modifier in the group Media.

Notes:

• For correct import into The Observer XT, the name of the attribute must be the same as the name of the object, including the case.
• It is not possible to import two or more attributes to the same object. For example, a stimulus object has two attributes, File (with the image file names as values) and CorrectAnswer (with values 1 or 2). For this object, you can import either the image file name or the correct response as a modifier, not both. In the first case you rename File as the object name, in the second you rename CorrectAnswer as the object name.
• It is not possible to change the name of the modifier group Media in The Observer XT.

Example 2: To Import Non-Filenames

A stimulus has an attribute named PictureType with possible values Positive and Negative defined in the Trial List. For each stimulus event, the corresponding value must be imported in The Observer XT as a modifier of the behavior Show Stimulus.

1. In E-Studio, open the experiment.
2. In the Experiment Explorer window, double-click the list in which the object is located.
3. In the list properties window, take note of the attribute that contains the values to import (in this example, PictureType).
4. Rename the object to match the attribute name that contains the values to import.

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Source: The Observer XT 17 - Technical Note - E-Prime