Not all research results get published. Sometimes results showing something other than what the researchers or the funders had hoped for not get published. Other times, the researchers have problems to find a suitable journal for their study.
While working towards a set goal, always other avenues opens up which requires bit more extra work to shape it as a good paper but either PI or funding agency are not interested about it. Moreover, PI feels it is unnecessary direction which distracts the original work and waste of time.
Another, important thing is, if you are mentioning/discussing this sort of extra bit of work for publication, sometime it'll damage your reputation as "always getting distracted instead of concentrating about assigned work".
Unpublished studies do face the bottlenecks as pointed.Eventually with acceptable modification within the confines of ethical boundary and following the journal criteria of the manuscript , the efforts can be successful.
The negative or unexpected results of a study should point out the exclusivity of a study anticipated to yield pre conceived results, and I find this even more interesting as it could be substantial contribution to research.
While working towards a set goal, always other avenues opens up which requires bit more extra work to shape it as a good paper but either PI or funding agency are not interested about it. Moreover, PI feels it is unnecessary direction which distracts the original work and waste of time.
Another, important thing is, if you are mentioning/discussing this sort of extra bit of work for publication, sometime it'll damage your reputation as "always getting distracted instead of concentrating about assigned work".