Table 5.

Execution times of the different cross-validation (CV) techniques

CV group	CV techniques	Execution time	Is the technique valid in this study?
Record-wise	Stratified k-folds CV	1 min	No
	Leave-one-out CV	6 hr 16 min 2 s	No
	Repeated stratified k-folds CV	4 min 49 s	No
Subject-wise	Stratified-group k-folds CV	1 min 10 s	Yes
	Leave-one-group-out CV	31 min 35 s	Yes
	Repeated stratified-group k-folds CV	4 min 59 s	Yes