diff --git a/app/models/mentor_management.rb b/app/models/mentor_management.rb
index 54a71096463..0adfdf5a468 100644
--- a/app/models/mentor_management.rb
+++ b/app/models/mentor_management.rb
@@ -3,7 +3,7 @@ class MentorManagement
   #
   # 1) Find all assignment participants for the
   #    assignment with id [assignment_id] whose
-  #    duty is the same as [Particpant#DUTY_MENTOR].
+  #    duty is the same as [Participant#DUTY_MENTOR].
   # 2) Count the number of teams those participants
   #    are a part of, acting as a proxy for the
   #    number of teams they mentor.
diff --git a/app/models/team.rb b/app/models/team.rb
index 2f79a4ab9e6..5f777f1f896 100755
--- a/app/models/team.rb
+++ b/app/models/team.rb
@@ -261,8 +261,7 @@ def self.export(csv, parent_id, options, teamtype)
       if options[:team_name] == 'false'
         team_members = TeamsUser.where(team_id: team.id)
         team_members.each do |user|
-          user_export = user.user.respond_to?(:username) ? user.user.username : user.user
-          output.push(user_export)
+          output.push(user.user.username)
         end
       end
       csv << output
diff --git a/app/views/assignments/edit/_rubrics.html.erb b/app/views/assignments/edit/_rubrics.html.erb
index 9802f11c179..c94fbf7a92c 100644
--- a/app/views/assignments/edit/_rubrics.html.erb
+++ b/app/views/assignments/edit/_rubrics.html.erb
@@ -19,7 +19,7 @@
         if (round_no == null && duty_id == undefined) {
             html += '<td><label for="questionnaire_id">' + questionnaire.display_type + ':</label></td>';
         } else if (round_no == null && duty_id != undefined) {
-            // E2147 : Add name of duty infront of the questionnaire type to select for which duty the questionnaire is being selected
+            // E2147 : Add name of duty in front of the questionnaire type to select for which duty the questionnaire is being selected
             html += '<td><label for="questionnaire_id">' + questionnaire.display_type +  ' Role ' + duty_name + ':</label></td>';
         }
         else if (round_no!=null && duty_id == undefined) {
diff --git a/app/views/shared_scripts/_user_list.html.erb b/app/views/shared_scripts/_user_list.html.erb
index 0a3ff3a3187..01d0657f695 100644
--- a/app/views/shared_scripts/_user_list.html.erb
+++ b/app/views/shared_scripts/_user_list.html.erb
@@ -16,7 +16,7 @@
     <th class="head">Submit</th>
     <th class="head">Review</th>
     <th class="head">Take quiz</th>
-    <!-- E2351 - on assignments, show the particpant's duty. header for this column -->
+    <!-- E2351 - on assignments, show the participant's duty. header for this column -->
     <% if params[:model] == 'Assignment' %>
       <th class="head">Mentor</th>
     <% end %>
diff --git a/lib/scoring.rb b/lib/scoring.rb
index e4eac5aa6c8..c0fc0f52a1d 100644
--- a/lib/scoring.rb
+++ b/lib/scoring.rb
@@ -86,7 +86,7 @@ def compute_total_score(assignment, scores)
   # Computes and returns the scores of assignment for participants and teams
   # Returns data in the format of
   # {
-  # :particpant => {
+  # :participant => {
   #   :<participant_id> => participant_scores(participant, questions),
   #   :<participant_id> => participant_scores(participant, questions)
   #   },
@@ -126,7 +126,7 @@ def review_grades(assignment, questions)
   # Return scores that this participant has been given
   # Returns data in the format of
   # {
-  #    :total_score => participant.grade ? particpant.grade : compute_total_score(assignment, scores)
+  #    :total_score => participant.grade ? participant.grade : compute_total_score(assignment, scores)
   #    :max_pts_available => topic.micropayment if assignment.topics?
   #    :participant => participant,
   #    :questionnaire_symbol1 => {
diff --git a/spec/models/user_spec.rb b/spec/models/user_spec.rb
index f89cadfd17c..a9ba7ecab8e 100644
--- a/spec/models/user_spec.rb
+++ b/spec/models/user_spec.rb
@@ -16,7 +16,7 @@
       expect(user).not_to be_valid
     end
     it 'Validate that username is always unique' do
-      expect(user1).to validate_uniqueness_of(:username)
+      expect(user1).to validate_uniqueness_of(:username).case_insensitive
     end
     it 'Validate that the username does not contain white spaces' do
       expect(user).to be_valid