Submitted on: 12 August 1999.
Revised on: 20 September 1999.
Accepted on: 14 October 1999.
___________________IEEE Transactions on Learning Technologies
Submitted on: 17 March 2005.
Revised on: 21 May 2005.
Accepted on: 02 June 2005.
___________________IEEE Transactions on Learning Technologies
Submitted on: 27 December 2011.
Revised on: 14 March 2012.
Accepted on: 27 April 2012.
___________________IEEE Transactions on Learning Technologies
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Submitted on: 30 November 2012.
Revised on: 29 March 2013.
Accepted on: 06 May 2013.
___________________IEEE Transactions on Learning Technologies
Submitted on: 05 February 2005.
Revised on: 22 March 2005.
Accepted on: 22 April 2005.
___________________IEEE Transactions on Learning Technologies
Submitted on: 15 September 2021.
Revised on: 27 December 2021.
Accepted on: 11 February 2022.
___________________IEEE Transactions on Learning Technologies