Hello every one,
We are a group of students working on a project related to surveys analysis.
We were wondering if with LimeSurvey, we can create a simple list of users (those who are going to respond to surveys), and then the admin make a specific survey for each one, these users in order to respond and give responses to these surveys should be authentificated ( login and password).
Thank you for your time.

Yes, that is possible.
www.limesurvey.org/manual/Survey_participants

We are also trying to make an app (Android, ...) that interact with LimeSurvey for normal clients use, so that they can answer the different surveys that they are requested to answer to, and we were wondering if there is manner to interface the communication (JSON format or API to integrate or other solution).
And if you have some solutions or advice, please don't hesitate to inform us.
Thank you for your response

FayezDebbabi wrote: wondering if there is manner to interface the communication (JSON format or API to integrate or other solution).

www.limesurvey.org/manual/RemoteControl_2_API

Okey, thank you very much.

I have read the Survey participants manual, and i was wondering if authenticating participants is only based on Tokens, and if not how to add for example an email based authentication (like user authentication when we send password and the user name in email, or other solutions).
An other question, if we access the survey only with a token, could a token be used unlimited number of times? or should we generate a non reachable number of tokens for example so that we can keep opening a survey? (What i want is just that a participant can answer surveys multiple times as long as he has access).
Thank you

You can set multiple uses for tokens - "Uses left - www.limesurvey.org/manual/Survey_partici...ing.2Fadding_a_token