You can also use "~에 대해서" between your friends, not exactly in formal situation...
" 내가 조선 시대 역사에 대해서 설명해 줄께. "
So if you find the difference of those phrases, "~에 대해서" is used in either oral and written style, formal or informal situation, but "~는 말이야" is not used in written style or formal situation. Besides it's not appropriate for the elderly. But it could be used in novel, not a report.