diff --git a/app/controllers/overview_controller.rb b/app/controllers/overview_controller.rb
index 8e78cd25..28dc4c6c 100644
--- a/app/controllers/overview_controller.rb
+++ b/app/controllers/overview_controller.rb
@@ -37,6 +37,6 @@ class OverviewController < SqmApplicationController
   end
 
   def categories
-    @categories ||= Category.sorted.includes(%i[measures admin_data_items subcategories])
+    @categories ||= Category.sorted.includes(%i[measures scales admin_data_items subcategories])
   end
 end
diff --git a/app/models/category.rb b/app/models/category.rb
index 318d3f5f..ad546a98 100644
--- a/app/models/category.rb
+++ b/app/models/category.rb
@@ -9,4 +9,5 @@ class Category < ActiveRecord::Base
   has_many :subcategories
   has_many :measures, through: :subcategories
   has_many :admin_data_items, through: :measures
+  has_many :scales, through: :subcategories
 end
diff --git a/app/models/response_rate_calculator.rb b/app/models/response_rate_calculator.rb
index 65731cff..d0dbab58 100644
--- a/app/models/response_rate_calculator.rb
+++ b/app/models/response_rate_calculator.rb
@@ -39,7 +39,11 @@ class ResponseRateCalculator
     response_count / survey_item_count.to_f
   end
 
+  def respondents
+    @respondents ||= Respondent.find_by(school:, academic_year:)
+  end
+
   def population_data_unavailable?
-    Respondent.where(school: @school, academic_year: @academic_year).count.zero?
+    @population_data_unavailable ||= respondents.nil?
   end
 end
diff --git a/app/models/student_response_rate_calculator.rb b/app/models/student_response_rate_calculator.rb
index f3d928f3..198ef9a9 100644
--- a/app/models/student_response_rate_calculator.rb
+++ b/app/models/student_response_rate_calculator.rb
@@ -17,15 +17,15 @@ class StudentResponseRateCalculator < ResponseRateCalculator
 
   def rates_by_grade
     @rates_by_grade ||= enrollment_by_grade.map do |grade, num_of_students_in_grade|
-      sufficient_survey_items = survey_items_with_sufficient_responses(grade:).keys
-      actual_response_count_for_grade = SurveyItemResponse.where(school:, academic_year:, grade:,
-                                                                 survey_item: sufficient_survey_items).count.to_f
-      count_of_survey_items_with_sufficient_responses = survey_item_count(grade:)
-      if count_of_survey_items_with_sufficient_responses.nil? || count_of_survey_items_with_sufficient_responses.zero? || num_of_students_in_grade.nil? || num_of_students_in_grade.zero?
+      responses = survey_items_with_sufficient_responses(grade:)
+      actual_response_count_for_grade = responses.values.sum.to_f
+      count_of_survey_items_with_sufficient_responses = responses.count
+      if actual_response_count_for_grade.nil? || count_of_survey_items_with_sufficient_responses.nil? || count_of_survey_items_with_sufficient_responses.zero? || num_of_students_in_grade.nil? || num_of_students_in_grade.zero?
         next nil
       end
 
-      [grade, actual_response_count_for_grade / count_of_survey_items_with_sufficient_responses / num_of_students_in_grade * 100]
+      rate = actual_response_count_for_grade / count_of_survey_items_with_sufficient_responses / num_of_students_in_grade * 100
+      [grade, rate]
     end.compact.to_h
   end
 
@@ -33,10 +33,6 @@ class StudentResponseRateCalculator < ResponseRateCalculator
     @enrollment_by_grade ||= respondents.enrollment_by_grade
   end
 
-  def total_enrollment
-    respondents.enrollment_by_grade.sum
-  end
-
   def survey_items_have_sufficient_responses?
     rates_by_grade.values.length.positive?
   end
@@ -46,24 +42,16 @@ class StudentResponseRateCalculator < ResponseRateCalculator
       threshold = 10
       quarter_of_grade = enrollment_by_grade[grade] / 4
       threshold = threshold > quarter_of_grade ? quarter_of_grade : threshold
-      memo[grade] = SurveyItem.joins('inner join survey_item_responses on  survey_item_responses.survey_item_id = survey_items.id')
+      memo[grade] = SurveyItem.joins("inner join survey_item_responses on  survey_item_responses.survey_item_id = survey_items.id")
                               .student_survey_items
                               .where("survey_item_responses.school": school, "survey_item_responses.academic_year": academic_year, "survey_item_responses.grade": grade, "survey_item_responses.survey_item_id": subcategory.survey_items.student_survey_items)
-                              .group('survey_items.id')
+                              .group("survey_items.id")
                               .having("count(*) >= #{threshold}")
                               .count
     end
     @survey_items_with_sufficient_responses[grade]
   end
 
-  def survey_item_count(grade:)
-    survey_items_with_sufficient_responses(grade:).count
-  end
-
-  def respondents
-    @respondents ||= Respondent.find_by(school:, academic_year:)
-  end
-
   def total_possible_responses
     @total_possible_responses ||= begin
       return 0 unless respondents.present?
diff --git a/app/models/teacher_response_rate_calculator.rb b/app/models/teacher_response_rate_calculator.rb
index a7524715..2cecce25 100644
--- a/app/models/teacher_response_rate_calculator.rb
+++ b/app/models/teacher_response_rate_calculator.rb
@@ -2,37 +2,27 @@
 
 class TeacherResponseRateCalculator < ResponseRateCalculator
   def survey_item_count
-    @survey_item_count ||= begin
-      survey_items = @subcategory.measures.flat_map(&:teacher_survey_items)
-
-      SurveyItem.joins('inner join survey_item_responses on  survey_item_responses.survey_item_id = survey_items.id')
-                .teacher_survey_items
-                .where("survey_item_responses.school": school, "survey_item_responses.academic_year": academic_year, "survey_item_responses.survey_item_id": survey_items)
-                .group('survey_items.id')
-                .having('count(*) >= 0').count.length
-    end
+    @survey_item_count ||= survey_items_with_sufficient_responses.length
   end
 
   def survey_items_have_sufficient_responses?
     survey_item_count.positive?
   end
 
+  def survey_items_with_sufficient_responses
+    SurveyItem.joins("inner join survey_item_responses on  survey_item_responses.survey_item_id = survey_items.id")
+              .teacher_survey_items
+              .where("survey_item_responses.school": school, "survey_item_responses.academic_year": academic_year, "survey_item_responses.survey_item_id": @subcategory.survey_items.teacher_survey_items)
+              .group("survey_items.id")
+              .having("count(*) >= 0").count
+  end
+
   def response_count
-    @response_count ||= @subcategory.measures.map do |measure|
-      measure.teacher_survey_items.map do |survey_item|
-        survey_item.survey_item_responses.where(school:,
-                                                academic_year:).exclude_boston.count
-      end.sum
-    end.sum
+    @response_count ||= survey_items_with_sufficient_responses.values.sum
   end
 
   def total_possible_responses
-    @total_possible_responses ||= begin
-      total_responses = Respondent.where(school:, academic_year:).first
-      return 0 unless total_responses.present?
-
-      total_responses.total_teachers
-    end
+    @total_possible_responses ||= respondents.total_teachers
   end
 
   def raw_response_rate