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Hello, I have recently started a study using LimeSurvey. I had a sample of 113 people. I got an e-mail from 1 participant saying the survey loaded slowly and that certain pictures did not appear within the 1 second time limit he wass given to view a picture. I kind of panicked so I previewed the survey from start to finish. I and my teammates used Chrome and Firefox and used 4  different computers and saw  nothing in terms of pictures not appearing or loading issues.

I also looked at the data and participants seemed to identify most pictures accurately in the recognition task and there was a statistically significant ieffect related to pictures in another task that also used pcitures.

My question is if there is something wrong with my survey that would cause this issue for certain people or if this person are due to issues with his own computer.

Thanks for your help

*My question is if there is something wrong with my survey that would cause this issue for certain people or if this person's problems are due to issues with his own computer.

The problem is probably that respondent's internet access speed.

It is really not necessary to repeat your question after half an hour.

But you answered your question yourself.

I got an e-mail from 1 participant saying the survey loaded slowly
...
I and my teammates used Chrome and Firefox and used 4  different computers and saw  nothing in terms of pictures not appearing

Have you never had the experience of a slow connection to a page that usually loads rather fast?

But there is one thing I am wondering about.
Why do you shrink all images to 20% instead of resizing them before?

Joffm 

 

I thought there was a syntaxic error in the text of the post. So I restated it, sorry.


The pictures were resized and checked to all be the same size before LimeSurvey upload. Our supervisor wanted the pictures to be a certain size so I think this is why they were shrunk by a research assistant subsequently using the source code in the questions. However, this aspect of the task was made 2 years ago.

I figured access speed was the likely culprit, I just wanted to cover all my bases. This is part of my thesis so I am being very careful.

Access speed aggravated by the fact to use bigger than necessary images, which means bigger file sizes, which means longer loading.

Always create the images in the size you need. If you only show them at 20% of their size, make the images smaller. This will reduce the size significantly.

With 1 second time I would always "preload" the images somewhere, because 1 second is really not much, when it comes to showing images. If the internet of a respondent isn't at its best one day, 1 second might not be enough for loading and showing the images and answer.

@holch
@Joffm

We had resized the pictures to be smaller before they were reduced by 20% to respond to the problem of them not loading fast enough within the 1 second when we were testing the survey. The pictures were 562 x 762 before being reduced to 112.4 x 152.4 at 20% of their size.The issue did not re-occur afterwards when we previewed the survey.

Do you still think the image size was problematic ?

As we don't have the images in the survey, we can't tell how big they are. But there is a good to fair chance that it was part of the problem.

We had resized the pictures to be smaller before they were reduced by 20% to respond to the problem

This doesn't even make sense. What did you do? When it comes to show images in a certain fixed size (not responsive), also make them the right size in a image editing software. The % in HTML only make them appear smaller, the file size is still the same.

OK, I am sorry, I misspoke. I meant that initially some of the pictures were too large and were brought down to 562 x 762 by editing the image files so that they would appear properly during the tasks. They were then put in the questions where they appeared at 20% of their size on LimeSurvey.

As I said, at the time, we previewed the survey after modifying the image files before re-upload to LS and the task functionned properly.
 

And I am sure it works properly for most. For those that have a bad internet connection the file size in MB might have an impact though.

hey were then put in the questions where they appeared at 20% of their size on LimeSurvey.

Still don't understand this 20%.

Resizing the image to 20% with CSS does not help. The browser will still load the full image. It's all about the file size in bytes of the full image. The image should be resized in editing software to the maximum viewed size and then optimized for web. This will result in the smallest file size (fewest bytes).

tpartner wrote:

Resizing the image to 20% with CSS does not help.

 

It sounds like they also did edit the images itself.

were brought down to 562 x 762 by editing the image files

These days it's really important to state which size (canvas or file) is reduced and where (HTML/CSS or Imagefile).

Beside a slow internet-connection, the rendering process of a browser can be delayed by backroundprocesses on the end-device too.
With a one second time limit for displaying images (if got that right), I wonder that only one person had issues.