What is the best approach for a survey that might have 2,000 responses?

I've built an application (angularjs) that registers a user (creates a userid and surveykey) and sends them to LimeSurvey to collect their responses to 90+ items. I use EM to summarize the items into 9 buckets, then redirect them back to the app to see the 3x3 matrix for their results.

Since I don't know who is going to sign-up for the assessment, I setup a Dummy Participant (5,000 uses) with a token I created to use as I build the user's link. Using Panel Integration, I capture their userid and my surveykey so I can tell which survey belongs to which user.

Problem #1: Lots of incomplete surveys
This works ok, but I have a bunch of incomplete surveys! This makes me wonder if something is crashing or if the user just gets tired of 90+ items. I don't know. I have seen Safari quite working in the middle of a survey--easily fixed by refreshing the page, but that's because I know how to do that...a lot of users in the wild are unfamiliar with reloading a page!

Problem #2: User Restarts
What I do know is several users are starting over! When they login to the app, if they haven't completed the survey, I send them back to the survey to complete it before going forward. The app is worthless without a completed survey.

Are my problems caused by my approach?

Should I dynamically add users with add_participants() and get tokens from LimeSurvey instead of creating my own surveykey?

Should I use my own method to add a participant with my surveykey?

I have two more in the works, so I'd appreciate any advice as I continue to learn LimeSurvey.

For starters, it looks like I need to insert users into the token table upon registration AND enable token-based response persistence (from the Survey Properties, Tokens section. This solves Problem #1 as it returns the user to finish an incomplete survey. This is HUGE!

So many features in LimeSurvey...just takes a while to figure out which ones to use.

Hi,

Don't think your method to create token linked to particpant change something to 1.
add_participants / autoCreateToken by plugin / hack DB directly etc ....

I have seen Safari quite working in the middle of a survey--easily fixed by refreshing the page

There are, maybe, an issue with one of your js or something else .....