The third model ignores any difference by tier, and considers only the role of understanding different content aspects of the concept.
But surely our vision and thus our work should be in understanding different races and cultures.
In 1963 he wrote for My Favorite Martian, another series about understanding different kinds of people.
I see them slowly transformed by understanding different perspectives and debating with one another using evidence and rational argument.
Teaching gave me a foundation: organisation, planning, understanding different learning styles and needs, the importance of good communication.
Pioneer in understanding different cultures, people with AIDS, rights of gays and lesbians, and Indian art.
"They know - as we do - that learning about other people and understanding different cultures is the key to a better school experience for everyone.
"I've always had this appreciation of different cultures, different races, and the importance of bridging that and understanding different points of views and perspectives," Tatum said.
He cited "Haggadah and History" (1975), which showed how Jewish history could be studied by understanding different editions of the Passover book through time.
"Because one of the benefits of travel is exposing people to different points of view, understanding different cultures," he said.
"More and more employers are wanting graduates to have a 'global mindset', which means understanding different cultures and how industries work across borders," says Stephen Isherwood, chief executive of the Association of Graduate Recruiters.
