Table 5.

Similarity measures

Similarity measure	Citation
Euclidean Distance Similarity	Imran et al. (2016), Bourkoukou and El Bachari (2016), Venkatesh and Sathyalakshmi (2020), Murad et al. (2020), Vanitha and Krishnan (2019)
Jaccard Coefficient	Senthilnayaki et al. (2015), Wan and Niu (2018), and Bourkoukou et al. (2016)
Cosine Similarity	Albatayneh et al. (2018), Bourkoukou et al. (2016), Tarus et al. (2017), Wan and Niu (2018),Nafea et al. (2019), Bourkoukou et al. (2017), Joy et al. (2019), Venkatesh and Sathyalakshmi (2020), and Riyahi and Sohrabi (2020)
Ontological Similarity	Saleena and Srivatsa (2015)
Pearson Correlation Coefficient	Tarus et al., (2018a, 2018b), Nafea et al. (2019), Riyahi and Sohrabi (2020), and Bourkoukou et al. (2016)
Learner Parameters-based Similarity	Dwivedi et al. (2018),