gistfile1.rb

<%= semantic_form_for @decision do |form| %>
  <%= form.inputs(:name => "Questions", :for => :answer_to_questions) do |field| %>
     <%= field.input :decision_question_id, :as => :hidden %>
     <%= field.input :decision_answer, :as => :radio, :collection => field.object.decision_question.decision_answers, :label => field.object.decision_question.text %>
  <% end %>

  <%= form.inputs do %>
    <%= form.input :category_id, :as => :hidden %>
  <% end %>
  <%= form.buttons do %>
    <%= form.commit_button %>
  <% end %>
<% end %>