child.rb

require File.expand_path(File.dirname(__FILE__) + "/parent.rb")
class Child < Parent
  def build_report
    report(:parent_value => parent_method)
  end
end

gistfile1.txt

()$scout test child.rb 
== This plugin doesn't have option metadata.
== You haven't provided any options for running this plugin.
== Output:
{:server_name=>"",
 :errors=>[],
 :snapshot=>"",
 :reports=>
  [{:fields=>{:parent_value=>"parent"},
    :created_at=>"2012-08-31 20:15:40",
    :local_filename=>nil,
    :plugin_id=>nil,
    :origin=>nil}],
 :config_path=>"/Users/itsderek23/.scout",
 :alerts=>[],
 :summaries=>[],
 :options=>[]}

parent.rb

class Parent < Scout::Plugin
  def build_report
    report(:parent_value => parent_method)
  end
  
  def parent_method
    "parent"
  end
end