Correct. In that example, the value attribute is bound to the element's age property. Basically, anything in {{}}. > <input value="{{firstName}} {{lastName}}">

Correct. In that example, the value attribute is bound to the element's age property. Basically, anything in {{}}. > <input value="{{firstName}} {{lastName}}"> This will work as you expect (http://jsbin.com/ecejiy/6/edit http://jsbin.com/ecejiy/6/edit). Plus, if either of those property values change, the input.value will be updated accordingly. By the way, you can also add/define your own syntax for MDV bindings: https://github.com/Polymer/mdv/blob/master/docs/syntax.md https://github.com/Polymer/mdv/blob/master/docs/syntax.md