Secondary school students achieve broad mastery of the curriculum if they are taught with methods appropriate to their learning styles and they devote significant effort to their studies. Thus, if such broad mastery is not achieved by the students in a particular secondary school, those students are not being taught with methods appropriate to their learning styles.
The conclusion can be properly drawn if it is assumed that as long as secondary school students are taught with methods appropriate to their learning styles, they will devote significant effort to their studies.