Thank your for your answer :-)! The research group in my participatory research project with "young elderlies/elderly people" prefered to be called citizens 60+, but we needed a lot of time to find together this term to write on the flyers for our initiatives ecc., there was a lot of resistance against the words seniors, elderly ecc., but no really proposals also from themselves how they would like to be called. In my dissertation I use "ältere Menschen" (elderly people), because it is the most used term in research for this group, but I really don't like call them in a way they won't to be called... Therefore I am wondering why I can't find any literature about this topic (i tried in German, English, Italian...) to discuss it in a appropriate way in my dissertation.... 

Thank you for your thoughts, advices and good wishes!

By their names, I would think!

I have served about 8 years on our local senior commission, and have been involved in at least 6 efforts to find a way to rename the Senior Center and senior commission to attract the "Baby Boomer" generation.  After considering many alternatives, we decided each time to just keep the current titles.  Cute phrases like "Oasis" or "young elderly" don't clearly indicate the core purpose of senior centers.  As one of the most senior, read very old, members, I was willing to change the name but not to something less clear.  Most high schoolers want to become seniors; there is nothing wrong with that term.  After my terms on the Senior Commission, I was appointed to the Historical Preservation Commission - is that a better possible title for seniors?   Is the Cemetery and Forgotten Souls Commission next in line?  For your research , if you can move beyond a survey of the viewpoints to identify basic rationales presented and personal histories to relate to those rationales, you might be on to some very interesting research.  Good luck.

May I suggest that you remove any reference to age:  It is a bias in the current cultures which a target person in the genre will usually object to. 

Ask yourself, why is it important that you “call” someone or something with an adjective that indicates what demographic group you are targeting?  Alternately try using action words to indicate what activity happens for someone or at a place.  If you’re meeting in the library to discuss a current topic just say so.  If you are having an exercise session aimed at persons with arthritis then say so.  Concentrate on what you are doing or where. 

Better to avoid the age prejudice altogether.  As for me?  You may call me Sir or Mr. Frech and if you are my friend you may use my first name.

thank you for your answers and advices!

I, too, like the accurate use of numbers. If you tell me I am in the "Age 60+" category, my thought is that you are correct. If you tell me I am in the "Senior" or "Elderly" category, I will take an immediate dislike to you.

Generally, any group becomes isolated by giving a mass designation.