Psychomotor Vigilance testing using Javascript

Assuming you can put each of the 8 samples on it's own page, you shouldn't have to use javascript as Qualtrics has a built in timing question. See the documentation page here: https://www.qualtrics.com/support/survey-platform/survey-module/editing-questions/question-types-guide/advanced/timing/

You can then use embedded data, piping, and math functions to calculate the respondent's average reaction time for the day.

* Piping: https://www.qualtrics.com/support/survey-platform/survey-module/editing-questions/piped-text/piped-text-overview/
Example:
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* Embedded Data: https://www.qualtrics.com/support/survey-platform/survey-module/survey-flow/standard-elements/embedded-data/
* Math Operations: https://www.qualtrics.com/support/survey-platform/survey-module/editing-questions/piped-text/math-operations/
I have trouble with the math operations always working when I put in parentheses so the screen shot of the survey flow is a broken out into steps for your calculation

Your Survey Flow will look like:
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And the survey itself will look like:
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I did this for 2 conditions but you can easily expand it to the 8 you want in your experiment.

Hints: when calculating sum you can pipe in the value from the timing question
1. Make sure you are selecting the value (so the variable without " - Description" after it)
2. Add spaces between variable names and +
3. the whole thing should be wrapped inside of $e{ }

You can use the same exact syntax for the Average variable.
If you want to do calculations on Sum and Average across respondents e.g. the Average of the average, then you need to go into Options in the green Embedded Data box and change Variable type from Text to Number Set.