The @Out not working with rich-component rich:picklist

[nimo22]

Hello,

I have tried to use that

@Out(required=false) private List <String> selectedValues;

with that:

<rich:pickList value="#{selectedValues}" >
<f:selectItems.../>
</rich:pickList>

It returns:
UISelectMany : must be of type List or Array ..

After that, I have tried to use getter and setter intead of @Out,
and do that:

<rich:pickList value="#{myBean.selectedValues}" >
<f:selectItems.../>
</rich:pickList>

then it works!(WHY does @Out not works but getter/setters?)

greetings