Suppose that there's a student who has done a subject-based study with ten participants involved. The research settings required not telling the participants that it has been a research before data collection (they participated in an online job interview, but there was no job in reality for them, so none of them got any job in fact [Attention: This was just an example. In reality, they only took an online translation test, at the time they desired.]). Can the researcher get their participants' consent for the inclusion of their data in the research after data collection? Would it be a problem for publication in journals?
As long as the study is IRB approved and the approved procedures are followed, then publication should not be a problem. It seems a little strange, but reasonable, that an IRB would aprove a protocol where minimal risk data collection was kept secret, but require informed consent prior to data analysis. I would have expected consent and debriefing to happen immediately following data collection, but again, if there is a reason to delay it, that seems fine.