Please help us help you and fill where relevant:
Your LimeSurvey version: Version 3.15.6+190108 (I know, this is far to old, but university installation, they are contemplating upgrading)
Own server or LimeSurvey hosting: Own, by Uni
Survey theme/template: Adapted Vanilla
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In my response data I see the following: lastpage = -1, but questions on the first page have been answered.
In other entries in the response tabel lastpage is also -1, but many more pages (groups) were filled in.

I also see 4 entries with lastpage = empty, but then no data is fileld in.

I can imagine a person that filled in and after that went to previous pages, but then I wonder: what does the variable lastpage mean?

tammo wrote:

I can imagine a person that filled in and after that went to previous pages, but then I wonder: what does the variable lastpage mean?
 

The definitions of lastpage I remember over the time are:
lastpage =  page number where respondent decided to quit the survey
lastpage =  the last page seen by respondent

The manual is missing a glossary, where variables and definitions can be found.
A start for response variables is this here:
manual.limesurvey.org/ExpressionFixedDbVar
 

Thank you jelo, this helps (a little...).

Still I wonder what empty or -1 means....

Seems that this is lacking in the manual indeed...

lastpage = Empty : Respondent visits Welcome-page and then leaves.

lastpage = -1: Respondent visits Welcome-page, clicks next, then go back to Welcome-page and then leaves without any answers.

OK, nearly there: what does lastpage = 0 mean then? I get confused...

lastpage = 0 : Respondent clicks next to come to the first page, but then leave.

But I don't see that the developers stick to that pattern. Perhaps non of the active developers have looked at that part.

If you try to reproduce the lastpage codes, you will find LimeSurvey versions which set "lastpage =empty" in cases where 0 would be expected.


The status "left survey" and "still answering survey" is technically the same. If the last time stamp is old enough we conclude the respondent has left. Or when the survey is closed. But that is the case for all web-applications.