What negative impacts changing language automatically in input fields can have on UX?

Question

For users who use more than one language a common pattern happens when they enter data into the computer:

• They write in one language until it's necessary to write in another language
• They use language changing shortcut to change keyboard's language
• They input data in the new language

On Windows for example the shortcut is Left Alt + Shift.

In the context of online forms that is mixed of fields with multiple languages, some developers do something creative. They automatically detect characters entered into the input box, and they change it to the equivalent character of the other language.

For example, if user has English layout selected for his keyboard and hits K key on keyboard when entering data into a field that needs to be filled with Persian characters, developers intercept that enter event and change the character to 'ن'.

This prevents users from requiring that language-layout switching and somehow does it automatically for them.

My question is, what drawbacks this creative approach can have on User Experience?

Answer 1

The same as with anything that comes with forces automation and lack of transparency. Because a semi-smart system will never be 100% correct.

One good example of a bad situation would be when you are writing in indian/Japanese but you want to specify product names in the original language. Windows for example, can be the glass in a wall, but it can also be the operating system. If the system automatically translates it to the local script it won't make as much sense. And the same goes for individual letters, EAN-codes etcetera.

Second big issue is that people might not be aware of the function. Which can lead to a lot of confusion and many other related issues.

A good rule of thumb is that if you want to make something sort-of-smart, it should be an option instead of an obligation. Easy if you want, but still allowing full control.