Would it be okay to use 2 SUS scores to come up with a single score in the case I explain below:
I conducted a user testing for a banking mobile app, the app under investigation has lots of tasks which stakeholders wants to look up so, in order to keep the testing session around an hour I divided the tasks in 2 groups. Each performed 5 tasks. After the test, each group was presented with SUS. I have 2 SUS scores in hand, one comes from Group 1 performed task A,B,C,D,E and other from Group 2 performed task F,G,H,I. All tasks belong to the same mobile app. Is it ok to get combine the results of these two in order end up with a single score for the app itself?