diff --git a/spec/controllers/exercises_controller_spec.rb b/spec/controllers/exercises_controller_spec.rb
index b509a33f..43dada43 100644
--- a/spec/controllers/exercises_controller_spec.rb
+++ b/spec/controllers/exercises_controller_spec.rb
@@ -313,30 +313,4 @@ describe ExercisesController do
       expect_template(:edit)
     end
   end
-
-  describe 'redirect after submit' do
-
-    let!(:submission_with_created_at_to_receive_feedback) { FactoryGirl.create(:submission, exercise_id: exercise.id, user_id: user.id, user_type: user.class.name, created_at: (11 - (user.id % 10))) }
-
-    let(:exercise_with_user_feedbacks) { FactoryGirl.build(:dummy_with_user_feedbacks, submission: submission_with_created_at_to_receive_feedback) }
-    let(:exercise_with_21_user_feedbacks) { FactoryGirl.build(:dummy_with_user_feedbacks, user_exercise_feedback_count: 21, submission: submission_with_created_at_to_receive_feedback)) }
-
-
-
-    it 'with less than maximal user feedbacks' do
-      exercise_with_user_feedbacks.send(:redirect_after_submit)
-      expect_redirect(new_user_exercise_feedback_path(user_exercise_feedback: {exercise_id: @exercise.id}))
-    end
-
-    it 'with more than maximal user feedbacks' do
-      exercise_with_user_feedbacks.send(:redirect_after_submit)
-      expect_redirect(new_user_exercise_feedback_path(user_exercise_feedback: {exercise_id: @exercise.id}))
-    end
-
-
-
-    expect_redirect(Exercise.last)
-
-  end
-
 end
diff --git a/spec/models/submission_spec.rb b/spec/models/submission_spec.rb
index 64f4e49e..227c6b99 100644
--- a/spec/models/submission_spec.rb
+++ b/spec/models/submission_spec.rb
@@ -85,4 +85,53 @@ describe Submission do
       expect(submission.to_s).to eq(described_class.model_name.human)
     end
   end
+
+  describe '#redirect_to_feedback?' do
+
+    context 'with no exercise feedback' do
+      let(:exercise) {FactoryGirl.create(:dummy)}
+      let(:user) {FactoryGirl.build(:external_user, id: (11 - exercise.created_at.to_i % 10) % 10)}
+      let(:submission) {FactoryGirl.build(:submission, exercise: exercise, user: user)}
+
+      it 'sends 10% of users to feedback page' do
+        expect(submission.send(:redirect_to_feedback?)).to be_truthy
+      end
+
+      it 'does not redirect other users' do
+        9.times do |i|
+          submission = FactoryGirl.build(:submission, exercise: exercise, user: FactoryGirl.build(:external_user, id: (11 - exercise.created_at.to_i % 10) - i - 1))
+          expect(submission.send(:redirect_to_feedback?)).to be_falsey
+        end
+      end
+    end
+
+    context 'with little exercise feedback' do
+      let(:exercise) {FactoryGirl.create(:dummy_with_user_feedbacks)}
+      let(:user) {FactoryGirl.build(:external_user, id: (11 - exercise.created_at.to_i % 10) % 10)}
+      let(:submission) {FactoryGirl.build(:submission, exercise: exercise, user: user)}
+
+      it 'sends 10% of users to feedback page' do
+        expect(submission.send(:redirect_to_feedback?)).to be_truthy
+      end
+
+      it 'does not redirect other users' do
+        9.times do |i|
+          submission = FactoryGirl.build(:submission, exercise: exercise, user: FactoryGirl.build(:external_user, id: (11 - exercise.created_at.to_i % 10) - i - 1))
+          expect(submission.send(:redirect_to_feedback?)).to be_falsey
+        end
+      end
+    end
+
+    context 'with enough exercise feedback' do
+      let(:exercise) {FactoryGirl.create(:dummy_with_user_feedbacks, user_feedbacks_count: 42)}
+      let(:user) {FactoryGirl.create(:external_user)}
+
+      it 'sends nobody to feedback page' do
+        30.times do |i|
+          submission = FactoryGirl.create(:submission, exercise: exercise, user: FactoryGirl.create(:external_user))
+          expect(submission.send(:redirect_to_feedback?)).to be_falsey
+        end
+      end
+    end
+  end
 end