Coherence Analysis

We outline next the main results of a coherence analysis of the experimental sessions. The first one is related to how coherent was the execution of the trials of each one of the tasks, and the second one is related to how coherent was the execution of the tasks among subjects. We proposed as metrics the number of selections, the number of missions, the distance traveled and the BCI usage (all of them normalized in time). The coherence is described by Pearson’s correlation coefficient, whose values close to one indicate strong coherence while values far from one indicate weak coherence.

On the one hand, the coherence between trials indicates the similitude grade among the two trials executed for each subject in each task. For all subjects, we computed the correlation of the previous metrics across trials. The result was that the coherence across subjects in the tasks is always greater than 0.98 indicating that the coherence among trials is very high. As conclusion, all the subjects used coherently the device to solve each task. On the other hand, the coherence between subjects indicates the similitude grade between the execution of the tasks. For all subjects, we computed the correlation of the previous metrics.

COHERENCE BETWEEN TRIALS AND SUBJECTS
	Task 1					Task 2
	S1	S2	S3	S4	S5	S1	S2	S3	S4	S5
S1	1	0.97	0.98	0.99	1	1	0.98	0.96	0.98	0.93
S2	-	1	0.99	0.96	0.93	-	1	0.97	0.97	0.95
S3	-	-	1	0.97	0.96	-	-	1	0.92	0.99
S4	-	-	-	1	0.93	-	-	-	1	0.87
S5	-	-	-	-	1	-	-	-	-	1

The coherence values are very high (always greater than 0.87). These results suggest that all the subjects used the device to solve the tasks coherently and in an analogous way.