Hi everyone,

I have been successfully (imho) using Limesurvey for three years and I love it. Thank you for your great work.
However, now, I have encountered an issue with which, please, maybe you could help me:

I used Limesurvey Version 3.15.6+190108 locally on XAMPP (Windows 10, 64-bit) to design a survey.
Limesurvey, of course, measures, reaction time for each page that is answered.
In my survey, I created several pages with text that forward automatically to the next page after 3 seconds. There is no option to interact with these pages.
I was hoping to measure a general latency of the hardware and internet setup of future online respondents to my survey.
Unfortunately, when I activated and tested the survey I realized that the reaction time measures vary considerably for these pages.
I tested three times and the reaction times varied between 3.69 and 4.91 seconds, although, of course, I tested the survey locally with the exact same setup and the pages forwarded each after 3 seconds.

Do you know if this is an error in Limesurvey?
Is there a way to prevent this, i.e. to suppress this variation of reaction time measurement?

Thank you so much,
Daniel

Webpages never load within the same time. There are so many factors that influence that (Browser, webserver, database server, OS, etc.).

I find 3.69 - 4.91 actually estonishingly good for your setup (even if you are running things locally, there are so many things that play into this.

I think if you want to run tests with the level of accuracy that you expect, you probably can only do it within a native application (not web based) and after a lot of testing.

I would always take the times in Limesurvey (or any other webbased survey system) with a grain of salt and I would definitely not rely on this if you need accurace of 1 second or less.

By the way: LS does not measure "reaction" time. But the time between when the page is loaded to when the respondend moves on from the page.

Thank you very much for your reply.
I realize that reaction times are an issue with online experiments. However, I was not expecting the maximum delay to be almost 200% higher than the lowest if the study is run locally with browser, server, OS, etc. all the same (and nothing else running in background). That's a bummer
Studies seem to suggest that they are more reliable (cf. URL: peerj.com/articles/1058/ )
Thanks again,
Daniel

I am not an expert on this, so wait until some more experienced users (like Tpartner & Denis) will skip in. However, in my experience, everything that has to do with web technology is generally always quite "unstable" when it comes to response time. You still have http and database connections, that might take sometimes longer, some times are quicker.

I guess when experiments are time sensitive, they should not be dependend on database connections, etc. You might be able to run them purely in the browser (e.g. via Javascript, Flash, etc) and only at the end transfer the timings etc. This is probably better when treating time sensitive experiments. But even then, with Javascript, at least a couple of years ago there were significant differences between the speek of how browsers rendered javascript code (if I remember right, Chrome was especially quick in doing so), etc.

Of course, with the same machine and browser, etc. this shouldn't impact too much, but I just wouldn't want to rely on it.

For showing a page during X seconds,

I think i use a
- Hide page during load
- Use learn.jquery.com/using-jquery-core/document-ready/ to show the page and start the counter
- Click next (and hide the page) when counter get 0


For body loading/loaded see
javascript : gitlab.com/SondagesPro/SurveyThemes/skel...s/skelvanilla.js#L85
css : gitlab.com/SondagesPro/SurveyThemes/skel.../skelvanilla.css#L31
html : gitlab.com/SondagesPro/SurveyThemes/skel...yout_global.twig#L25

Hi, thank you for your reply. However, I'm sorry, I can't follow.
Do you suggest that I should not use the timer provided by Limesurvey but jquery?
Unfortunately, I'm not familiar with jquery. I have to write the code in the question's source code, right?
I would appreciate a lot if you could elaborate.
Thank you so much

I couldn't find an option in Limesurvey to 'hide the during loading' (only 'hide question'?)

ultimatte wrote: …
Do you suggest that I should not use the timer provided by Limesurvey but jquery?
…

Sorry, i didn't know you use LimeSurvey timer .

Maybe you can test importing skelvanilla theme and test with it.

gitlab.com/SondagesPro/SurveyThemes/skelvanilla
dl.sondages.pro/skelvanilla.zip

Thank you!
I tested it. Unfortunately, I still get a considerable variance in page load times with your theme although your theme seems slightly better: 3.78-4.82s with Vanilla; 4.2-5.2s with Skelvanilla.
Please, do you have another suggestion?

Apart from this, your theme looks great and I would like to use it. However, I need the grey background from Vanilla as I present images with white background. Could you please tell me how to get the grey background back in your theme?
Thanks a lot

Loook at theme option : you have whole boostswatch included.
And here : you can choose "well" for question wrapper.

And you can make your own theme with gitlab.com/SondagesPro/SurveyThemes/less-skelvanilla (but need css/less compentency)