Knowledge Base

Interface and Visualization

Pane Controls

You have the following options for managing panes in NoldusHub 1.8:

• Hover with the mouse between the panes, and drag and drop to rescale.
• Hover with the mouse over the panes and click the full screen button to open the panes in full screen. Click again to exit the full screen.
• Hover over the panes, click and hold the tab with the data signal that you want to move and drag the panes to the preferred spot, drop the panes at the corresponding location.

Replaying a Session

1. Scroll to the session you want to replay and click the corresponding button or on the name.
2. Optional: Click + Add signal... inside the Timeline pane to select additional data signals to display in Timeline.
   1. Select or clear the data signal checkboxes you want to select or deselect.
   2. Click the confirm button.
3. Start the replay by clicking the play button inside the Timeline pane.
4. Optional: You can add markers to your recording.

What's Next?

Downloading a session or adding a marker to your recording would be logical next steps.

Download, Rename or Delete a Session

Aim

To download the recorded session data or to rename or delete a recorded session.

Background

You can download the recorded session data for further processing in other software. For example, you can import the downloaded data into Excel or SPSS as input for (statistical) analysis. Or you can delete a session if the recording went wrong or for another reason.

Before You Begin

The download and delete a session functionality depends on your application-level user role:

• As an Administrator you can download a session for any project.
• As a Researcher you can download a session for projects you created yourself and for projects shared with you as a member.
• As a User you can download a session for projects shared with you as a member.

Navigate to the project from which you want to download a session.

Download a Session

1. Click Sessions.
2. Scroll to the session you want to download and click the corresponding download button. All data streams (CSV-files) checkbox is automatically selected.
3. Optional: If you want to download the screen and face video as well, select the All videos checkbox.
4. Click Download. Chrome downloads the files. The CSV-files are stored in a combined ZIP file. And the screen and webcam footage in separate MP4 files. NoldusHub prefixes the file names with the session name for easy reference. The Zip file contains a separate CSV file for each device, for example eyetracking.csv and facialexpressions.csv.

Note: To play the exported MP4 files, in principle, any media player supporting MP4 can be used. However, as of NoldusHub 1.7, the _screencapture.mp4 files have a very limited number of key frames for episodes in which there was no movement in the captured screen. Not all media players can cope equally well with that. In our experience, "Windows Media Player legacy" works best, "PotPlayer", "KM Player" and "GOM Player" work sufficiently well and the Microsoft "Media Player" app and the "VLC Media Player" show many artifacts in navigation and playback and can therefore better be avoided.

Rename a Session

1. To rename your session, click the rename button on the session you want to rename.
2. Enter the new name for your session in the Name field.
3. Click Save.

Delete a Session

1. Click Sessions.
2. Scroll to the session you want to delete and click the corresponding delete button.
3. Click Yes.

Hide or Show Navigation Bar

Aim

To hide or show the navigation bar that is located on the left side of the application.

Hide Navigation

1. Before you open a project, a limited left navigation will be displayed.
2. Once you open a project, the full navigation bar is visible on the left.
3. To collapse the navigation bar, click the arrow button pointing to the left at the bottom of the navigation panel.
4. To hide the icons of the navigation bar as well, click the button with the arrow pointing to the left again.

Show Navigation

1. To expand the navigation once it is fully hidden, click the button with the arrow pointing to the right.
2. To expand the navigation from the icon view, click the button with the arrow pointing to the right again.

Restart the NoldusHub System

In some cases, the NoldusHub server may become unstable, for instance:

• Video is not recorded
• Facial expression data is missing
• Live streaming fails

Before You Begin

If such problems occur and persist, restarting the system is a last resort solution. For that, you must have the Administrator role to have access to the server. For a bare-metal server system, that requires entering an account name and password. For a system attached to a company network, this requires an IP address, Username and Password to set up a remote desktop connection.

Close N-Linx Agent on the Participant Station

1. Go to the system tray, find N-Linx agent, right click on it, and click Exit.

Verify That All Components Are Closed on the Participant Station

1. Open Windows Task Manager and click the Details tab.
2. Close all processes called N-Linx Agent or ps.exe by right clicking on each of these and selecting "End task".

Execute StopNoldusHub.bat on the Server

1. Navigate to C:\Program Files\Noldus\NoldusHub\.
2. Double click StopNoldusHub.bat and wait until all services are stopped.
3. Once all services are stopped, press Enter or close the window.

Execute StartNoldusHub.bat on the Server

1. In the same folder on the Server, double click StartNoldushub.bat.
2. When all services are started, press Enter or close the window.

Wait 3 Minutes and Then Start the Participant Station(s)

1. After starting the server, wait for 3 minutes.
2. On all participant stations, one after the other, search for "N-Linx agent" in the search box in the task bar on the participant station.
3. Select and start N-Linx agent, and check in the system tray whether the icon has appeared. If this is not the case, repeat the starting of N-Linx agent.
4. Double click on the N-Linx agent entry and check the statuses of all device plugins. These should now all be online.

If any of these steps fails and NoldusHub cannot be restarted, please contact Noldus Support.

Supported Devices

The following types of devices are supported in NoldusHub 1.8:

• Eye trackers
• Biosensors
• Webcams

Eye Trackers

The following eye trackers currently on the market are supported in NoldusHub:

Tobii Pro (Current Models)

• Spark - 60 Hz.
• Fusion - 30 Hz, 60 Hz, 120 Hz, 250 Hz.
• Spectrum - 60 Hz, 120 Hz, 150 Hz, 300 Hz, 600 Hz or 1200 Hz. NoldusHub supports the 60 Hz setting.

The following eye trackers are discontinued by their manufacturer but are still supported in NoldusHub (up to 60 Hz):

Tobii Pro (Discontinued Models)

• Nano - 60 Hz.
• X2-30
• X2-60
• X60
• X120
• T60
• T120

Eyetech

• VT3-mini - 40 Hz, 120 Hz. Firmware version 2019.2.3.0_19.11.22.72. NoldusHub supports 40 Hz and 120 Hz settings.

Biosensors

The following biosensors currently on the market are supported in NoldusHub:

Shimmer3 EXG Unit

Supported signals:

• Raw ECG Lead I (referenced to Lead Neutral)
• Raw ECG Lead II (referenced to Lead Neutral)
• Raw ECG Lead III (referenced to Lead Neutral)
• Raw ECG Lead IV (referenced to Lead Neutral)
• Heart rate (calculated from the ECG Lead II signal)
• Interbeat intervals (calculated from the ECG Lead II signal)

Shimmer3 GSR+ Unit

Supported signals:

• Raw PPG
• Heart rate (calculated from the raw PPG signal)
• Interbeat intervals
• Tonic skin conductance
• Skin conductance peak rate

Shimmer biosensors require correct configuration during the installation of the NoldusHub participant stations. Problems with one or all signals from your Shimmer device may be caused by misconfiguration (e.g. sampling frequency settings and signal selections on the device). Your system administrator can check that configuration using the NoldusHub installation documentation for Shimmer devices.

Webcams

Logitech

• Brio webcam, VGA resolution.

Frequently Asked Questions (FAQ)

Below is a list of Frequently Asked Questions. Is your question not on this list? Reach out to Noldus support via the MyNoldus customer portal for assistance.

Timeline

Why Are Some Signals Not Displayed in Real Time?

Some signals are running behind compared to other signals as they are not raw data but preprocessed data. This is the case for EDA signals, for example. The EDA data comes in later than the other data. This is normal and has to do with the processing that takes place to plot this data.

How Many Researchers Can Use NoldusHub Simultaneously?

NoldusHub version 1.4–1.7 both allow two researchers to work in parallel.

What Is the Maximum Length of the Sessions That I Can Record?

The maximum length of the sessions that can be recorded in NoldusHub 1.4–1.6 is 90 minutes or 1.5 hours.

Why Do I Not See Any Signals in the Timeline During Replay?

In versions 1.4–1.6, this could happen if you did not record EDA data during a session. Click on the + Add signal button and deselect all EDA signals. Go back to your replay and all your signal data should now be visible.

Why Do I Not See Any Cognitive Load Data?

Make sure to calibrate the eye tracker before each session. Although there is the option to Skip Calibration, please consider always calibrating if cognitive load data is desired.

Markers

Why Am I Not Seeing Markers That I Defined in the Marker Pane?

To define markers it is important to click the Save button to store them. Otherwise, your markers will be lost.

Eye Tracking

How Should the Participant Be Seated for Eye Tracking?

For accurate eye tracking results, take note of the following recommendations:

• The participant should be facing straight toward the center of the screen.
• For Tobii Pro eye trackers: the height of the eyes should be at one-third from the top of the monitor. The distance between eyes and eye tracker should be approximately 65 cm. Sitting at an arm's length from the monitor is approximately the correct distance.
• For Eyetech VT3 Mini: the height of the eyes should be halfway down the monitor. The distance between eyes and eye tracker should be approximately 60 cm. Use the measuring tape supplied by Eyetech.
• To optimize the head position towards the eye tracker, use a table or chair that can be adjusted in height.
• During the test, let the participant be seated as still as possible. Do not use a chair with wheels.
• Make sure that the participant can read items on the screen and, if needed, can easily reach the keyboard and mouse.
• Take care that lighting from windows, or other light sources, does not interfere with the eye tracking.
• The angle between the eye tracker and the gaze point at the screen is maximally 36° and ideally 20°. In general, when the participant is seated at the correct distance and height in front of the monitor, the angle is correct.

Why Am I Not Receiving Eye Tracker Data?

• If you have an Eyetech eye tracker, it could be that you did not calibrate the eye tracker. The Eyetech eye tracker does not provide data prior to calibration. Calibrate the Eyetech eye tracker and see if this fixes your issue. If not, reach out to your system administrator or Noldus Support.
• If you have a Tobii eye tracker, follow the instructions to install the eye tracker as described by Tobii. If you still run into problems, reach out to your system administrator or Noldus Support.

Why Are the Calibration Dots Not Distributed Evenly Across the Participant Screen?

When the calibration screen does not look as expected — for example, if the calibration dots are all in one corner — check your Windows display scale. It should be set to 100%. If the display scaling is set to 100% but problems still occur, do the following:

1. Disconnect the eye tracker from the participant PC.
2. Reconnect the eye tracker.
3. Restart the participant PC.
4. Refresh the browser page on the test leader PC.

Why Is the Calibration Failing?

If calibration fails, or calibration quality is repeatedly not good enough, this may be due to several reasons:

• The participant is not seated correctly in front of the computer. The participant may be sitting at an angle to the monitor or sitting at an incorrect height or distance. Use a table or chair that is easily adjustable in height. Do not use a chair with wheels or a swivel chair, because the participant may change position during either the calibration or test, leading to incorrect eye tracking data.
• The participant does not correctly follow the dots during the calibration. This may result in a deviation between the displayed calibration dots and the measured gaze data (low accuracy). Ask the participant to focus on the dots and not anticipate where the dots may appear.
• The ambient lighting may not be optimal. Avoid overhead light and bright sunlight in the experiment room.
• The eye tracker may not correctly detect the eyes. Make sure the eyes are not (partially) covered by hair. Also, opening the eyes wider may help. Be aware that thick black mascara, bifocal or multifocal glasses, and reflective glasses may cause problems with eye tracking.
• The eye tracker may be dirty. This may result in large gaze circles in the calibration results plot (low precision). Clean the eye tracker gently. Please refer to the documentation that came with your eye tracker for cleaning instructions. Disconnect your eye tracker from the power source before cleaning. Do not use strong cleaning agents, and ensure the eye tracker does not become wet.
• If you use the Eyetech VT3 Mini, it is essential that both of the green lights on the eye tracker light up during the entire calibration. This means that both eyes are detected during the whole calibration.

Why Do I Observe Gaze and Fixation Values Lower Than 0.0 and Higher Than 1.0?

Gaze and fixation values outside the range of 0.0 to 1.0 indicate that the gaze point is outside the boundaries of the screen. This can occur when a participant looks away from the screen or when eye tracking accuracy is reduced due to poor calibration or incorrect seating position. Review the participant seating guidelines and recalibrate the eye tracker if necessary.

Why Does Screen Sharing Not Work?

If screen sharing is not working, verify that the necessary permissions and network settings are correctly configured. Contact your system administrator or Noldus Support if the issue persists.

Why Does My Biosensor Not Work?

Problems with one or all signals from your biosensor may be caused by misconfiguration, such as incorrect sampling frequency settings or signal selections on the device. Your system administrator can check that configuration using the NoldusHub installation documentation for the respective biosensor.

How Can I Back Up My NoldusHub Data?

For information on backing up NoldusHub data, contact your system administrator or reach out to Noldus Support via the MyNoldus customer portal.

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Source: NoldusHub 1.8 Reference Manual