<li id='new_criterion'>
  <%= form_tag assignment_criteria_path(assignment_id: assignment.id),
               method: :post,
               remote: true do %>
    <div id='new_criterion_error' style='display:none;' class='error'></div>
    <%= label_tag 'new_criterion_prompt',
		              t('criteria.name') %><br>
    <%= text_field_tag(:new_criterion_prompt,
                       '',
                       size: 15) %><br>
    <%= label_tag 'new_criterion_type_prompt',
                  t('criteria.type') %><br><br>
    <%= radio_button_tag(:criterion_type,
                         'RubricCriterion',
                         checked = true) %>
    <%= label_tag(:rubric_criterion,
                  t('criteria.rubric')) %>
    <%= radio_button_tag(:criterion_type,
                         'FlexibleCriterion',
                         checked = false) %>
    <%= label_tag(:flexible_criterion,
                  t('criteria.flexible')) %><br><br>
    <%= submit_tag(t('criteria.save'), data: { disable_with: t('working') }) %>
  <% end %>
</li>

<li id='new_criterion'>
  <%= form_tag assignment_criteria_path(assignment_id: assignment.id),
               method: :post,
               remote: true do %>
    <div id='new_criterion_error' style='display:none;' class='error'></div>
    <%= label_tag 'new_criterion_prompt',
		              t('criteria.name') %><br>
    <%= text_field_tag(:new_criterion_prompt,
                       '',
                       size: 15) %><br>
    <%= label_tag 'new_criterion_type_prompt',
                  t('criteria.type') %><br><br>
    <%= radio_button_tag(:criterion_type,
                         'RubricCriterion',
                         checked = true) %>
    <%= label_tag('criterion_type_RubricCriterion',
                  t('criteria.rubric')) %>
    <%= radio_button_tag(:criterion_type,
                         'FlexibleCriterion',
                         checked = false) %>
    <%= label_tag('criterion_type_FlexibleCriterion',
                  t('criteria.flexible')) %><br><br>
    <%= submit_tag(t('criteria.save'), data: { disable_with: t('working') }) %>
  <% end %>
</li>

Fix labels for different criteria types @GitGeminiano
Fix labels for different criteria types @GitGeminiano
