Table 6.

Internal split-half consistency (bootstrapped Cronbach’s alpha) per task in the OCS-Plus from 320 neurologically healthy adults.

Measure	Alpha
Picture naming	0.23
Semantics	0.17
Orientation	0.04
Encoding 1	0.41*
Encoding 2	0.67*
Delayed recall	0.10
Delayed recall and recognition	1*
Incidental episodic memory	0.06
Trails baseline	0.71*
Trails switching	0.87*
Rule finding	1*
Cancellation	0.96*
Invisible cancellation	0.96*
Figure copy	0.94*
Figure Recall	0.93*

Oxford Cognitive Screen-Plus (OCS-Plus). We used 5000 iterations of bootstrapped randomly split-half sampled trail level data to calculate internal consistency. *Refer to reliability ratings we interpret due to the test assumptions being met. Trails baseline and switching conditions are included here to elude to reliability of the executive score which has no trial level data as it is a ratio of baseline and switching performance. Low item sub-tasks have unreliable internal consistency measures due to disproportionate effect of one mistake, making interpretation of the subtask’s reliability difficult, however, test–retest stability suggests all tests are stable across time.