Submitted on: 25 November 2012.
Revised on: 15 February 2013.
Accepted on: 28 March 2013.
___________________Computers and Education Open---ELSEVIER
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Submitted on: 28 April 2021.
Revised on: 22 June 2021.
Accepted on: 07 August 2021.
___________________Computers and Education Open---ELSEVIER
Submitted on: 07 August 2019.
Revised on: 03 September 2019.
Accepted on: 25 September 2019.
___________________Computers and Education Open---ELSEVIER
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Submitted on: 08 April 2004.
Revised on: 03 June 2004.
Accepted on: 28 July 2004.
___________________Computers and Education Open---ELSEVIER
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Submitted on: 11 December 2023.
Revised on: 03 January 2024.
Accepted on: 20 February 2024.
___________________Computers and Education Open---ELSEVIER
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