Weber’s Law

When we redesign a product, we should think about how the users adapt to the changes. Usually, if your product has a drastic change, no matter how good the new design is, the users would still think the old one is better. This is a natural human behaviour.

Just Noticeable Difference

What you should do instead is — change gradually, so gradually that the users could not see a significant difference. This helps them adapt to and accept the new design.