[lookit-research] stimulus sound not coming through on videos

[Lisa Oakes]

Hi David (and everyone):

Online testing has such promise and yet has new frustrations.

First, what you are experiencing is not a lookit problem.  Computers suppress what it interprets as background noise when recording. We have found that we hear the sound pretty reliably for some experiments but not for others, and sometimes we hear some sounds but not others. I suspect it depends on the nature of the sound and the volume. Bottom line: it doesn’t matter how you are recording, if you collect data online you can’t depend on hearing the sound of the stimuli.

Moreover, even if you do hear sound, it is likely out of sync with the video. You may notice that when you see a child speak what you hear is out of sync with the video. Again, this is variable and there is no easy way to correct it. This is a known problem with video recording and with Lookit. You can find more info here: https://lookit.readthedocs.io/en/develop/researchers-lag-issues.html

A better solution is to use the timing info provided by lookit. However, this also is not exact. We (and others) have done extensive testing of the timing of stimulus presentations in lookit and have found that there is some variation in when stimuli start relative to when lookit says they start. I don’t think this has been solved and I don’t think it is known why it happens.

We have tested hundreds of kids using online methods for the last 3 years and my recommendations are (1) don’t rely on sound for timing, and (2) online methods are best for stimuli that are static or if it doesn’t matter when the infant looks relative to what is happening in the stimulus.

This probably isn’t the answer you wanted, but I hope it is helpful as you find a solution.

Lisa

Lisa M. Oakes
Professor, Department of Psychology
Faculty Researcher, Center for Mind and Brain
University of California, Davis
267 Cousteau Place
Davis, CA 95618

phone:  530 754-4523 OR
530 754-8304
Pronouns: she/her/hers

[cid:42BAFC46-1CBF-4718-B59D-003D4D71FFAA at cmb.ucdavis.edu]

On Mar 18, 2023, at 8:45 AM, Lewkowicz, David <david.lewkowicz at yale.edu<mailto:david.lewkowicz at yale.edu>> wrote:

Dear Melissa,

Recently, we have noticed that the participant videos recorded by Lookit seem to filter out the stimulus sounds that we normally present in our videos. We use these sounds to mark the beginning of a trial when we code the participant videos and, thus, their absence makes it impossible for us to reliably code the participant videos.  Are you aware of this and, if so, is there a fix for this problem?

Thanks very much in advance for looking into this problem.

Best regards,
David & Dick

__________________________________________
David J. Lewkowicz, Ph.D.
Senior Scientist
Haskins Laboratories, New Haven, CT
Yale Child Study Center
Personal: https://haskinslabs.org/people/david-lewkowicz
Lab: http://llamblab.haskins.yale.edu/


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