Complex sentence: The Australian Tertiary Admission Rank (ATAR) is the primary criterion for entry into most undergraduate-entry university programs in Australia, gradually introduced during 2009 and 2010 to replace the Universities Admission Index, Equivalent National Tertiary Entrance Rank and Tertiary Entrance Rank.
Split into simpler sentences: The Australian Tertiary Admission Rank (ATAR) is the primary criterion for entry into most undergraduate-entry university programs, to be gradually introduced during 2009 and 2010. It will replace the Universities Admission Index, Equivalent National Tertiary Entrance Rank and Tertiary Entrance Rank.