erroneous

ɪˈrəʊnɪəs
ɛˈrəʊnɪəs

adjective

wrong; incorrect.

employers sometimes make erroneous assumptions

wrong,incorrect,mistaken,in error,inaccurate,not accurate,inexact,not exact,imprecise,invalid,untrue,false,fallacious,wide of the mark,off target,misleading,illogical,unsound,specious,unfounded,without foundation,faulty,flawed,spurious,off beam,bogus,phoney,out,way out,full of holes,dicey,iffy,dodgy,abroad