module while loop

gistfile1.txt

module Text
  def self.print_string(text)
    puts "\n*** #{text} ***"
  end

  def self.chomp_it
    gets.chomp
  end
end

module Validate
  def self.valid_choice?(choice)
    if ['p', 'r', 's'].include?(choice.downcase)
      true
    else
      print_string "Enter a valid choice. Please try again"
    end
  end

  def self.valid_decision?(the_decision)
    if ['y', 'n'].include?(the_decision.downcase)
      return true
    else
      print_string "You must enter Y or N. Please try again"
    end
  end
end

begin
  Text.print_string "Choose one: P/R/S"
  choice = Text.chomp_it
end while !Validate.valid_choice?(choice)

*** Choose one: P/R/S ***
as
NoMethodError: undefined method `print_string' for Validate:Module
	from (irb):16:in `valid_choice?'
	from (irb):40
	from /Users/knoxjeffrey/.rvm/rubies/ruby-2.0.0-p598/bin/irb:12:in `<main>'