undefined method `speaker' for #<Af::Show:0x00000100b38098>

#<Af::Presentation id: nil, title: nil, speaker: nil, speaker_title: nil, company: nil, show_id: 9, created_at: nil, updated_at: nil>
Title

  <div class="field">
    <%= f.label :speaker %><br />
    <%= f.text_field :speaker %>
  </div>
  <div class="field">
    <%= f.label :speaker_title %><br />
    <%= f.text_field :speaker_title %>
  </div>
  <div class="field">
    <%= f.label :company %><br />
    <%= f.text_field :company %>
  </div>

All of them fail