“…Aerts et al, 2003;Edwards and Nelson, 2001;Leitner and Buttenfield, 2000;MacEachren et al, 1998;Nadav-Greenberg et al, 2008;Retchless, 2012;Schweizer and Goodchild, 1992;Slocum et al, 2003), transparency (e.g. Drecki, 2002;Newman and Lee, 2004;Slocum et al, 2003;Viard et al, 2011), or colour saturation that is used in a number of studies (e.g. Drecki, 2002;Kubíček and Šašinka, 2011;Kunz et al, 2011;Leitner and Buttenfield, 2000;Retchless, 2012;Sanyal et al, 2009).…”