Serialized Hash in Strong Parameters

result_set.rb

class ResultSet < ActiveRecord::Base
  belongs_to :survey
  belongs_to :student
  accepts_nested_attributes_for :survey


  attr_accessor :score, :correct_count, :total_count, :percent

  serialize :serial
end

result_sets_controller.rb

class ResultSetsController < ApplicationController
  before_filter :new

  def index

    @quiz_id = ResultSet.all.map { |u| [u.survey.name, u.survey_id]}.uniq
    @quiz_student_name = ResultSet.all.map { |u| [u.student.user.name, u.student_id]}.uniq

    if current.loginable_type == 'Student'
    @student_only = params[:student_id] = current_user.loginable.id
    end

    runquery = ResultSet
    runquery = runquery.where(:survey_id => params[:id]) if params[:id].present?
    runquery = runquery.where(:student_id => params[:student_id]) if params[:student_id].present?
    runquery = runquery.select('result_sets.*')

    @query = runquery

    @query.each do |a|

      @arr = []
      @actual = []
      @correct = []
      @score = []


      a.serial.to_a.each do |key,value|
        @actual << value
      end

      a.survey.questions.each do |b|

        @id = b.answers
        @id.each do |c|

          if c.correct == true
            @correct = @arr << c.id
          end
        end
      end

      # Virtual Attributes for View
      @score = @correct.collect{|x| "#{x}"} & @actual
      a.correct_count = @score.count.to_f
      a.total_count = @actual.count.to_f
      a.percent = (a.correct_count / a.total_count) * 100

    end

  end

  def new
    @result_set = ResultSet.new
  end

  def create
    @result_set = ResultSet.new(result_set_params)
    @result_set.save!
    if @result_set.save
      redirect_to result_sets_path, notice: "Quiz Completed Successfully"
    else
      redirect_to result_sets_path, notice: "There was a problem, Quiz not saved."
    end
  end

  def show
  end


  private

  def result_set_params
    params.require(:result_set).permit(:id, :student_id, :survey_id, :created_at, :updated_at, :serial => {}, survey_attributes: [:id, :name, :created_at, :updated_at, :student_id])

  end
end

show.html.erb

<h1><%= @survey.name %></h1>

<%= simple_form_for @result_set, url: result_sets_path do |f| %>

<ol class="questions">
  <% @survey.questions.each do |question| %>
      <li>
        <%= question.content %>
        <ol class="answers">
          <% question.answers.each do |answer| %>
              <li><%= answer.content %> <input type="radio" name="result_set[serial][<%= question.id %>]" value="<%= answer.id %>" style="margin-top:-2px;" /></li>
          <% end %>
        </ol>
      </li>
  <% end %>
</ol>

<%= f.input :student_id, :as => "hidden", :input_html => { :value => current_user.loginable.id } %>
<%= f.input :survey_id,  :as => "hidden", :input_html => { :value => @survey.id } %>
<%= f.submit 'Done', :class => 'btn btn-primary' %>

<% end %>

<% if current.loginable_type != 'Student'  %>
<%= link_to 'Edit', edit_survey_path(@survey) %> |
<% end %>
<%= link_to 'Back to Surveys', surveys_path %>