Positive transfer happens when you start to do a task similar to a task that what you have already done. You are familiarized with that kind of task and can use an acquired ability or experience during perfoming of a task in performing another similar task. Negative transfer is the opposit, happens when you can’t transfer an experience of performing a task to another similar task because the process is different.
Consistency is the root of this case. Keep the consistency and follow the patterns in the user inteface allow positive transfer and an inconsistent user interface design can be a source of negative transfer.
When users have developed ingrained skills, or well-rehearsed methods of control, they can impede performance on proceeding tasks in which similar skills or manoeuvres are necessary – Interaction Design Foundation
Inconsistency induces more errors, slows down task performance (efficiency), forces the user to resort to a more conscious and effortful mode of operation because the user must to identify “how does it work?”. In other way, consistency allow the user to carry out tasks quickly or even automatically (“without think”), reducing the error possibilities or bad user experiences.
Consistency should be avoided when unconscious, repeat selections need to be prevented. It’s common in dialogs where we ask the user if he is sure of an action. “Are you sure that you want to delete this item?”. Normally, the Ok button is showed left of the Cancel button, it’s a pattern, but if you want to prevent the user click on Ok automatically,without really think in what he is doing, you can break the consistency and change the buttons aside.