Question & Answers associations

Answer.rb

class Answer < ActiveRecord::Base
  belongs_to :respondent
  belongs_to :question
end

Comment.rb

class Comment < ActiveRecord::Base
  belongs_to :respondent
  belongs_to :question
end

Question.rb

class Question < ActiveRecord::Base
  has_many :comments
  has_many :answers
end

Respondent.rb

class Respondent < ActiveRecord::Base
  has_many :comments
  has_many :answers
end