Blue White Porcelain Dish with Big Crack

[elizabeth]

Got this plate from a friend who was cleaning out an estate... she was about to throw away this plate but I wanted to do some investigating on it.    For starters does it look old?    The bottom does not look like I would expect as it not glazed and a somewhat rough.  There is no old dirt or discoloration.      It is a line in the place where I would expect a signature.  The crack does not go all the way across so it was never repaired.    I do not see any little dots or pock marks.   
Want to know if it junk or worthy of further investigations. 

Thanks much in advance. 

[Stan]

Hi Elizabeth, this looks like Taisho period to me, the outside bottom of the foot would be more rounded if it were earlier, not straight on the outside of the foot rim.