diff --git a/README.mdown b/README.mdown
index 81bdfa1e..c33ffdb2 100644
--- a/README.mdown
+++ b/README.mdown
@@ -344,6 +344,7 @@ Split.configure do |config|
   config.enabled = true
   config.persistence = Split::Persistence::SessionAdapter
   #config.start_manually = false ## new test will have to be started manually from the admin panel. default false
+  config.include_rails_helper = true
 end
 ```
 
diff --git a/lib/split.rb b/lib/split.rb
index f876b119..25cbae61 100755
--- a/lib/split.rb
+++ b/lib/split.rb
@@ -7,6 +7,7 @@
    helper
    metric
    persistence
+   encapsulated_helper
    trial
    version].each do |f|
   require "split/#{f}"
diff --git a/lib/split/configuration.rb b/lib/split/configuration.rb
index e0eaaaac..011fffd9 100644
--- a/lib/split/configuration.rb
+++ b/lib/split/configuration.rb
@@ -17,6 +17,7 @@ class Configuration
     attr_accessor :on_trial_complete
     attr_accessor :on_experiment_reset
     attr_accessor :on_experiment_delete
+    attr_accessor :include_rails_helper
 
     attr_reader :experiments
 
@@ -118,6 +119,10 @@ def normalized_experiments
           if goals = value_for(settings, :goals)
             experiment_config[experiment_name.to_sym][:goals] = goals
           end
+
+          if (resettable = value_for(settings, :resettable)) != nil
+            experiment_config[experiment_name.to_sym][:resettable] = resettable
+          end
         end
 
         experiment_config
@@ -172,13 +177,14 @@ def initialize
       @experiments = {}
       @persistence = Split::Persistence::SessionAdapter
       @algorithm = Split::Algorithms::WeightedSample
+      @include_rails_helper = true
     end
 
     private
 
     def value_for(hash, key)
       if hash.kind_of?(Hash)
-        hash[key.to_s] || hash[key.to_sym]
+        hash.has_key?(key.to_s) ? hash[key.to_s] : hash[key.to_sym]
       end
     end
 
diff --git a/lib/split/encapsulated_helper.rb b/lib/split/encapsulated_helper.rb
new file mode 100644
index 00000000..4797c809
--- /dev/null
+++ b/lib/split/encapsulated_helper.rb
@@ -0,0 +1,58 @@
+# Split's helper exposes all kinds of methods we don't want to
+# mix into our model classes.
+#
+# This module exposes only two methods
+#  - ab_test and 
+#  - ab_test_finished
+# that can safely be mixed into any class.
+#
+# Passes the instance of the class that it's mixed into to the
+# Split persistence adapter as context.
+#
+module Split
+  module EncapsulatedHelper
+
+    class ContextShim
+      include Split::Helper
+      def initialize(context, original_params)
+        @context = context
+        @_params = original_params
+      end
+      def ab_user
+        @ab_user ||= Split::Persistence.adapter.new(@context)
+      end
+      def params
+        @_params
+      end
+    end
+
+    def ab_test(*arguments)
+      ret = split_context_shim.ab_test(*arguments)
+      # TODO there must be a better way to pass a block straight
+      # through to the original ab_test
+      if block_given?
+        if defined?(capture) # a block in a rails view
+          block = Proc.new { yield(ret) }
+          concat(capture(ret, &block))
+          false
+        else
+          yield(ret)
+        end
+      else
+        ret
+      end
+    end
+
+    def ab_test_finished(*arguments)
+      split_context_shim.finished *arguments
+    end
+
+    private
+
+    # instantiate and memoize a context shim in case of multiple ab_test* calls
+    def split_context_shim
+      _params = defined?(params) ? params : {}
+      @split_context_shim ||= ContextShim.new(self, _params)
+    end
+  end
+end
diff --git a/lib/split/engine.rb b/lib/split/engine.rb
index 692655f1..04392e76 100644
--- a/lib/split/engine.rb
+++ b/lib/split/engine.rb
@@ -1,8 +1,10 @@
 module Split
   class Engine < ::Rails::Engine
     initializer "split" do |app|
-      ActionController::Base.send :include, Split::Helper
-      ActionController::Base.helper Split::Helper
+      if Split.configuration.include_rails_helper
+        ActionController::Base.send :include, Split::Helper
+        ActionController::Base.helper Split::Helper
+      end
     end
   end
-end
\ No newline at end of file
+end
diff --git a/spec/configuration_spec.rb b/spec/configuration_spec.rb
index 568c8453..44b429f5 100644
--- a/spec/configuration_spec.rb
+++ b/spec/configuration_spec.rb
@@ -86,7 +86,7 @@
         end
 
         it 'should normalize experiments' do
-          @config.normalized_experiments.should == {:my_experiment=>{:alternatives=>["Control Opt", ["Alt One", "Alt Two"]]}}
+          @config.normalized_experiments.should == {:my_experiment=>{:resettable=>false,:alternatives=>["Control Opt", ["Alt One", "Alt Two"]]}}
         end
       end
 
@@ -112,7 +112,7 @@
         end
 
         it "should normalize experiments" do
-          @config.normalized_experiments.should == {:my_experiment=>{:alternatives=>[{"Control Opt"=>0.67},
+          @config.normalized_experiments.should == {:my_experiment=>{:resettable=>false,:alternatives=>[{"Control Opt"=>0.67},
             [{"Alt One"=>0.1}, {"Alt Two"=>0.23}]]}, :another_experiment=>{:alternatives=>["a", ["b"]]}}
         end
 
@@ -139,7 +139,7 @@
         end
 
         it "should normalize experiments" do
-          @config.normalized_experiments.should == {:my_experiment=>{:alternatives=>["Control Opt", ["Alt One", "Alt Two"]]}}
+          @config.normalized_experiments.should == {:my_experiment=>{:resettable=>false,:alternatives=>["Control Opt", ["Alt One", "Alt Two"]]}}
         end
       end