In general, I try to limit use of dropdowns to lists of no more than ~15 or so options. For larger lists with options the user is familiar with, I tend to favor autocomplete text inputs. However, I've come across a situation where I need to allow the user to select from a list of ~50 or more options with which he/she is not very familiar.
Because they are not familiar with the options, an autocomplete would leave the user confused and frustrated as they try in vain to guess the right spelling. Displaying ~50 plus options in a dropdown would make for poor UX, as it would require scrolling.
Is there an alternative approach? (bearing in mind that the UI needs to be as compact as possible)
Edit: The user will only ever be selecting one option.