“…Similarly, there are studies which indicate that homework behavior can vary depending on the topic studied (Trautwein & Lüdtke, 2007, 2009. In this century, multilevel studies have refined this relationship and shown that time spent has little effect on results (De Jong, Westerhof, & Creemers, 2000;Farrow, Tymms, & Henderson, 1999;Murillo & Martínez-Garrido, 2013;Núñez, Vallejo, Rosário, Tuero, & Valle, 2014) and, with statistical significance, the effect is negative (Chang, Wall, Tare, Golonka & Vatz, 2014;Trautwein, 2007;Trautwein, Köller, Schmitz, & Baumert, 2002;Trautwein, Schnyder, Niggli, Neumann, & Lüdtke, 2009). These studies show that students who have more difficulty learning or concentrating need more time to do their homework.…”