How to validate Quiz Questions Form Rails

I have a pretty basic form that shows quiz questions along with choices:

<%= form_tag(quiz_attempts_path, :method =>'post') %>
    <% @course_step.step.step_quiz.step_quiz_questions.each do |quiz_question| %>
        <h3><%= quiz_question.value %></h3>

        <% quiz_question.step_quiz_question_choices.each do |quiz_question_choice| %>
        <%= radio_button_tag("quiz_questions[#{quiz_question.id}]", quiz_question_choice.value, false)%>
        <%= quiz_question_choice.value%><br />
        <% end %>

    <% end %>
    <%= hidden_field_tag('step_quiz_id', @course_step.step.step_quiz.id)%>
    <%= hidden_field_tag('started', Time.now.utc)%>
    <%= submit_tag("Submit Quiz")%>
</form>

When I save the result for the form, I only save summary data: (Do I need to validate the data coming in to this method with some sort of model?)

def create
    correct = 0
    incorrect = 0
    params[:quiz_questions].each do |step_quiz_question_id, chosen_answer|
      if StepQuizQuestion.find(step_quiz_question_id).correct?(chosen_answer)
        correct += 1
      else
        incorrect += 1
      end
    end

    QuizAttempt.create(:patient_id => current_user.id, :correct => correct, :incorrect => incorrect, :started =开发者_如何学Go> params[:started], :ended => Time.now, :step_quiz_id => params[:step_quiz_id])
  end

Below is my quiz attempt model that I am saving to.

class QuizAttempt < ActiveRecord::Base
  belongs_to :step_quiz
  belongs_to :patient

  attr_accessible :step_quiz_id, :patient_id, :started, :ended, :correct, :incorrect  
end


# == Schema Information
#
# Table name: quiz_attempts
#
#  id           :integer         not null, primary key
#  step_quiz_id :integer
#  patient_id   :integer
#  started      :datetime
#  ended        :datetime
#  correct      :integer
#  incorrect    :integer
#  created_at   :datetime
#  updated_at   :datetime
#

How would you validate the form without doing a lot of code?

Is my general approach to this correct?

I think a better approach could be the nested fields approach.

You can have a very good start on this here (part 1) and here (part 2) with exactly your scenario, a survey with questions and answers.

For the validation you need to provide more information for what kind of validation you need.