1. ReDCAD Laboratory; University of Sfax, Sfax, Tunisia and Information Retrieval and Knowledge Management Research Lab, York University; 4700 Keele Street Toronto Ontario M3J 1P3 Canada
2. ReDCAD Laboratory, University of Sfax; Sfax Tunisia
3. School of Information and Communication Technology, Seneca College, Toronto, Canada and Information Retrieval and Knowledge Management Research Lab, York University; 4700 Keele Street Toronto Ontario M3J 1P3 Canada
4. Information Retrieval and Knowledge Management Research Lab, School of Information Technology, York University; 4700 Keele Street Toronto Ontario M3J 1P3 Canada