However, only a few randomised empirical studies have been conducted on the effects of
the development of multiple solutions on students’ achievements. Most of these studies were
based on the assumption that the construction of multiple solutions is important for learning
mathematics. Thus, they investigated which instructional method has to be used to teach
students to find multiple solutions. The findings have supported theoretical considerations
from cognitive science about the central role of linking together the different solutions that
were prompted in class. Students who compared and contrasted different solutions of the same
problem were found to outperform their classmates who reflected on each solution one at a
time (Rittle-Johnson & Star, 2007). Prior knowledge, kind of representations, and complexity
of the problems were identified as contextual factors that influence the effect of comparing
different solutions on students’ progress in mathematics (Große & Renkl, 2006; Reed, Stebick,
Comey, & Carroll, 2012; Rittle-Johnson, Star, & Durkin, 2009)