Usability factor

No. of items

Cronbach’s alpha*

Cronbach’s alpha**

Learnability

4

0.775

0.811

Efficiency

6

0.872

0.772

Effectiveness

4

0.857

0.778

Satisfaction

2

0.677

0.690

Errors

2

0.740

0.706

Privacy

2

0.771

0.737

Design

2

0.702

0.712