Generally, capitalize longer words. But this really depends on the style book you choose to follow (MLA, APA, CMOS). See: https://en.wikipedia.org/wiki/Title_ca

Generally, capitalize longer words. But this really depends on the style book you choose to follow (MLA, APA, CMOS). See: https://en.wikipedia.org/wiki/Title_case https://en.wikipedia.org/wiki/Title_case