CSC/ECE 517 Fall 2015/oss E1562 APS

E1562. Refactor AssignmentParticipant model<ref>https://docs.google.com/document/d/1uWs3zyrupTmrOFuv5IbVWCF4NRvCXqJmg8dZ0wCqgus</ref>

This page provides a brief description of the Expertiza project. The project is aimed at refactoring the AssignmentParticipant model which is subclass of Participant model. This model is used to maintain the list of students/users participating in a given assignment. For any new or existing assignments, this model manages the entire list of users assigned to that particular assignment. It primarily includes method for scores calculations, assignment submission paths, reviews, etc. As part of this project, some of the methods have been removed which were not being used anywhere, some have been moved to their appropriate helper module and some have been refactored into smaller ones.

Introduction to Expertiza

Expertiza is a peer review based system which provides incremental learning from the class. This project has been developed together by faculty and students using Ruby on Rails framework. Expertiza allows the instructor to create, edit and delete assignments, create new assignment topics, assign them to a particular class or selected students, have students work on teams and then review each other's assignments at the end. For the students, they can signup for topics, form teams, and submit their projects and assignments. Students then review the work done by other students and give suggestions to improve. Teams after reviews are allotted scores and they can refer to the peer comments to further improve their work. It also supports submission of different file types for assignments, including the URLs and wiki pages.

Why refactoring?

Refactoring[1] is restructuring of code without the need of changing any external behavior. It reduces complexity and improves readability. It also becomes easy to extend the application with respect to different modules and their functionalities. Some common techniques to refactor are:

• Moving methods to appropriate modules
• Breaking methods into more meaningful functionality
• Creating more generalized code.
• Renaming methods and variable.
• Inheritance

Project Description

Refactor AssignmentParticipant model which is a subclass of Participant model. The following tasks have been performed as per the requirements.

• Refactor scores method to smaller methods.
• In set_handle method, there is no need for a separate ELSEIF statement. Club the ELSEIF statement into IF statement as an another OR condition.
• Remove methods like compute_quiz_scores(scores) , average_score_per_assignment(assignment_id) which are not being used.
• Method cycle_deviation_score(cycle) is also present in CollusionCycle, remove it from this class.
• Methods related to reviews like teammate_reviews, bookmark_reviews do not belong to AssignmentParticipant model. Move them to the appropriate class.
• Methods related to files and directories like files(directory) should not be present in AssignmentParticipant model, move them to FileHelper module.

Refactoring

Scores method

The method scores has been converted to smaller methods scores, assignment_questionnaires, merge_scores, calculate_scores. It is a good practice to keep the methods not extremely long as they tend to complicate the functionality and the readability.

Old code

def scores(questions)

   scores = {}
   scores[:participant] = self
   self.assignment.questionnaires.each do |questionnaire|
     round = AssignmentQuestionnaire.find_by_assignment_id_and_questionnaire_id(self.assignment.id, questionnaire.id).used_in_round
     #create symbol for "varying rubrics" feature -Yang
     if(round!=nil)
       questionnaire_symbol = (questionnaire.symbol.to_s+round.to_s).to_sym
     else
       questionnaire_symbol = questionnaire.symbol
     end

     scores[questionnaire_symbol] = {}

     if round==nil
       scores[questionnaire_symbol][:assessments] = questionnaire.get_assessments_for(self)
     else
       scores[questionnaire_symbol][:assessments] = questionnaire.get_assessments_round_for(self,round)
     end
     scores[questionnaire_symbol][:scores] = Answer.compute_scores(scores[questionnaire_symbol][:assessments], questions[questionnaire_symbol])
   end

   scores[:total_score] = self.assignment.compute_total_score(scores)

   #merge scores[review#] (for each round) to score[review]  -Yang
   if self.assignment.varying_rubrics_by_round?
     review_sym = "review".to_sym
     scores[review_sym] = Hash.new
     scores[review_sym][:assessments] = Array.new
     scores[review_sym][:scores] = Hash.new
     scores[review_sym][:scores][:max] = -999999999
     scores[review_sym][:scores][:min] = 999999999
     scores[review_sym][:scores][:avg] = 0
     total_score = 0
     for i in 1..self.assignment.get_review_rounds
       round_sym = ("review"+i.to_s).to_sym
       if scores[round_sym][:assessments].nil? || scores[round_sym][:assessments].length==0
         next
       end
       length_of_assessments=scores[round_sym][:assessments].length.to_f

       scores[review_sym][:assessments]+=scores[round_sym][:assessments]

       if(scores[round_sym][:scores][:max]!=nil && scores[review_sym][:scores][:max]<scores[round_sym][:scores][:max])
         scores[review_sym][:scores][:max]= scores[round_sym][:scores][:max]
       end
       if(scores[round_sym][:scores][:min]!= nil && scores[review_sym][:scores][:min]>scores[round_sym][:scores][:min])
         scores[review_sym][:scores][:min]= scores[round_sym][:scores][:min]
       end
       if(scores[round_sym][:scores][:avg]!=nil)
         total_score += scores[round_sym][:scores][:avg]*length_of_assessments
       end
     end

     if scores[review_sym][:scores][:max] == -999999999 && scores[review_sym][:scores][:min] == 999999999
              scores[review_sym][:scores][:max] = 0
              scores[review_sym][:scores][:min] = 0
     end

     scores[review_sym][:scores][:avg] = total_score/scores[review_sym][:assessments].length.to_f
   end

   # In the event that this is a microtask, we need to scale the score accordingly and record the total possible points
   # PS: I don't like the fact that we are doing this here but it is difficult to make it work anywhere else
   if assignment.is_microtask?
     topic = SignUpTopic.find_by_assignment_id(assignment.id)
     if !topic.nil?
       scores[:total_score] *= (topic.micropayment.to_f / 100.to_f)
       scores[:max_pts_available] = topic.micropayment
     end
   end

   # for all quiz questionnaires (quizzes) taken by the participant
   quiz_responses = Array.new
   quiz_response_mappings = QuizResponseMap.where(reviewer_id: self.id)
   quiz_response_mappings.each do |qmapping|
     if (qmapping.response)
       quiz_responses << qmapping.response
     end
   end
   #scores[:quiz] = Hash.new
   #scores[:quiz][:assessments] = quiz_responses
   #scores[:quiz][:scores] = Answer.compute_quiz_scores(scores[:quiz][:assessments])

   scores[:total_score] = assignment.compute_total_score(scores)
   #scores[:total_score] += compute_quiz_scores(scores)

   # move lots of calculation from view(_participant.html.erb) to model
   if self.grade
     scores[:total_score] = self.grade
   else
     total_score = scores[:total_score]
     if total_score > 100
       total_score = 100
     end
     scores[:total_score] = total_score
   scores
   end
 end

New code

• scores(questions) method

def scores(questions)

   scores = {}
   scores[:participant] = self

   assignment_questionnaires(questions, scores)

   scores[:total_score] = self.assignment.compute_total_score(scores)

   merge_scores(scores)

   # In the event that this is a microtask, we need to scale the score accordingly and record the total possible points
   # PS: I don't like the fact that we are doing this here but it is difficult to make it work anywhere else
   if assignment.is_microtask?
     topic = SignUpTopic.find_by_assignment_id(assignment.id)
     if !topic.nil?
       scores[:total_score] *= (topic.micropayment.to_f / 100.to_f)
       scores[:max_pts_available] = topic.micropayment
     end
   end

   # for all quiz questionnaires (quizzes) taken by the participant
   quiz_responses = Array.new
   quiz_response_mappings = QuizResponseMap.where(reviewer_id: self.id)
   quiz_response_mappings.each do |qmapping|
     if (qmapping.response)
       quiz_responses << qmapping.response
     end
   end
   #scores[:quiz] = Hash.new
   #scores[:quiz][:assessments] = quiz_responses
   #scores[:quiz][:scores] = Answer.compute_quiz_scores(scores[:quiz][:assessments])

   scores[:total_score] = assignment.compute_total_score(scores)
   #scores[:total_score] += compute_quiz_scores(scores)

   calculate_scores(scores)
 end

• assignment_questionnaires(questions, scores) method

def assignment_questionnaires(questions, scores)

   self.assignment.questionnaires.each do |questionnaire|
     round = AssignmentQuestionnaire.find_by_assignment_id_and_questionnaire_id(self.assignment.id, questionnaire.id).used_in_round
     #create symbol for "varying rubrics" feature -Yang
     if(round!=nil)
       questionnaire_symbol = (questionnaire.symbol.to_s+round.to_s).to_sym
     else
       questionnaire_symbol = questionnaire.symbol
     end

     scores[questionnaire_symbol] = {}

     if round==nil
       scores[questionnaire_symbol][:assessments] = questionnaire.get_assessments_for(self)
     else
       scores[questionnaire_symbol][:assessments] = questionnaire.get_assessments_round_for(self,round)
     end
     scores[questionnaire_symbol][:scores] = Answer.compute_scores(scores[questionnaire_symbol][:assessments], questions[questionnaire_symbol])
   end
 end

• merge_scores(scores) method

def merge_scores(scores)

   #merge scores[review#] (for each round) to score[review]  -Yang
   if self.assignment.varying_rubrics_by_round?
     review_sym = "review".to_sym
     scores[review_sym] = Hash.new
     scores[review_sym][:assessments] = Array.new
     scores[review_sym][:scores] = Hash.new
     scores[review_sym][:scores][:max] = -999999999
     scores[review_sym][:scores][:min] = 999999999
     scores[review_sym][:scores][:avg] = 0
     total_score = 0
     for i in 1..self.assignment.get_review_rounds
       round_sym = ("review"+i.to_s).to_sym
       if scores[round_sym][:assessments].nil? || scores[round_sym][:assessments].length==0
         next
       end
       length_of_assessments=scores[round_sym][:assessments].length.to_f

       scores[review_sym][:assessments]+=scores[round_sym][:assessments]

       if(scores[round_sym][:scores][:max]!=nil && scores[review_sym][:scores][:max]<scores[round_sym][:scores][:max])
         scores[review_sym][:scores][:max]= scores[round_sym][:scores][:max]
       end
       if(scores[round_sym][:scores][:min]!= nil && scores[review_sym][:scores][:min]>scores[round_sym][:scores][:min])
         scores[review_sym][:scores][:min]= scores[round_sym][:scores][:min]
       end
       if(scores[round_sym][:scores][:avg]!=nil)
         total_score += scores[round_sym][:scores][:avg]*length_of_assessments
       end
     end

     if scores[review_sym][:scores][:max] == -999999999 && scores[review_sym][:scores][:min] == 999999999
       scores[review_sym][:scores][:max] = 0
       scores[review_sym][:scores][:min] = 0
     end

     scores[review_sym][:scores][:avg] = total_score/scores[review_sym][:assessments].length.to_f
   end
 end

• calculate_scores(scores) method

def calculate_scores(scores)

   # move lots of calculation from view(_participant.html.erb) to model
   if self.grade
     scores[:total_score] = self.grade
   else
     total_score = scores[:total_score]
     if total_score > 100
       total_score = 100
     end
     scores[:total_score] = total_score
     scores
   end
 end

set_handle method

The set_handle method had an unncessary ELSIF statement which was performing the same action self.handle = self.user.name. This has been clubbed as an OR condition to the IF statement and the first ELSIF statement has been removed.

Old code

def set_handle

     if self.user.handle == nil or self.user.handle == ""
       self.handle = self.user.name
     elsif AssignmentParticipant.where(parent_id: self.assignment.id, handle: self.user.handle).length > 0
       self.handle = self.user.name
     else
       self.handle = self.user.handle
     end
     self.save!

end

New code

def set_handle

     if self.user.handle == nil or self.user.handle == "" or AssignmentParticipant.where(parent_id: self.assignment.id, handle: self.user.handle).length > 0
       self.handle = self.user.name
     else
       self.handle = self.user.handle
     end
     self.save!

end

File and directory methods

The files and directory methods from AssignmentParticipant model have been moved to the FileHelper module. The methods files, submitted_files and dir_path are appropriate for the FileHelper' module and hence been moved there. The below line was added to the AssignmentParticipant model. include FileHelper

The AssignmentParticipant class would like class AssignmentParticipant < Participant

 require 'wiki_helper'
 include FileHelper

Methods moved to FileHelper:

• submitted_files

def submitted_files

   files(self.path) if self.directory_num
 end

• files(directory)

def files(directory)

   files_list = Dir[directory + "/*"]
   files = Array.new

   files_list.each do |file|
     if File.directory?(file)
       dir_files = files(file)
       dir_files.each{|f| files << f}
     end
     files << file
   end
   files
 end

• submitted_files()

def submitted_files()

   files = Array.new
   if(self.directory_num)
     files = files(self.path)
   end
   return files
 end

• dir_path

def dir_path

   assignment.try :directory_path
 end

Remove unused methods

The following methods have been removed as they were not being used by the application.

def average_score_per_assignment(assignment_id)

def average_score_per_assignment(assignment_id)
   return 0 if self.response_maps.size == 0

   sum_of_scores = 0

   self.response_maps.metareview_response_maps.each do |metaresponse_map|
     if !metaresponse_map.response.empty? && response_map == assignment_id then
       sum_of_scores = sum_of_scores + response_map.response.last.average_score
     end
   end

   (sum_of_scores / self.response_maps.size).to_i
 end

def quiz_taken_by?(contributor, reviewer)

def quiz_taken_by?(contributor, reviewer)

   quiz_id = QuizQuestionnaire.find_by_instructor_id(contributor.id)
   return QuizResponseMap.where(['reviewee_id = ? AND reviewer_id = ? AND reviewed_object_id = ?',
                                 self.id, reviewer.id, quiz_id]).count > 0
 end

def has_quiz?

def has_quiz?

   return !QuizQuestionnaire.find_by_instructor_id(self.id).nil?
 end

def reviewees

def reviewees

   reviewees = []
   rmaps = ResponseMap.all(conditions: ["reviewer_id = #{self.id} && type = 'ReviewResponseMap'"])
       rmaps.each { |rm| reviewees.concat(AssignmentTeam.find(rm.reviewee_id).participants) }

   reviewees
 end

def two_node_cycles

def two_node_cycles

   cycles = []
   self.reviewers.each do |ap|
     if ap.reviewers.include?(self)
       self.reviews_by_reviewer(ap).nil? ? next : s01 = self.reviews_by_reviewer(ap).get_total_score
       ap.reviews_by_reviewer(self).nil? ? next : s10 = ap.reviews_by_reviewer(self).get_total_score
       cycles.push([[self, s01], [ap, s10]])
     end
   end
   cycles
 end

def three_node_cycles

def three_node_cycles

   cycles = []
   self.reviewers.each do |ap1|
     ap1.reviewers.each do |ap2|
       if ap2.reviewers.include?(self)
         self.reviews_by_reviewer(ap1).nil? ? next : s01 = self.reviews_by_reviewer(ap1).get_total_score
         ap1.reviews_by_reviewer(ap2).nil? ? next : s12 = ap1.reviews_by_reviewer(ap2).get_total_score
         ap2.reviews_by_reviewer(self).nil? ? next : s20 = ap2.reviews_by_reviewer(self).get_total_score
         cycles.push([[self, s01], [ap1, s12], [ap2, s20]])
       end
     end
   end
   cycles
 end

def four_node_cycles

def four_node_cycles

   cycles = []
   self.reviewers.each do |ap1|
     ap1.reviewers.each do |ap2|
       ap2.reviewers.each do |ap3|
         if ap3.reviewers.include?(self)
           self.reviews_by_reviewer(ap1).nil? ? next : s01 = self.reviews_by_reviewer(ap1).get_total_score
           ap1.reviews_by_reviewer(ap2).nil? ? next : s12 = ap1.reviews_by_reviewer(ap2).get_total_score
           ap2.reviews_by_reviewer(ap3).nil? ? next : s23 = ap2.reviews_by_reviewer(ap3).get_total_score
           ap3.reviews_by_reviewer(self).nil? ? next : s30 = ap3.reviews_by_reviewer(self).get_total_score
           cycles.push([[self, s01], [ap1, s12], [ap2, s23], [ap3, s30]])
         end
       end
     end
   end
   cycles
 end

def cycle_similarity_score(cycle)

def cycle_similarity_score(cycle)

   similarity_score = 0.0
   count = 0.0

   0 ... cycle.size-1.each do |pivot|
     pivot_score = cycle[pivot][1]
     similarity_score = similarity_score + (pivot_score - cycle[other][1]).abs
     count = count + 1.0
   end

   similarity_score = similarity_score / count unless count == 0.0
   similarity_score
 end

def cycle_deviation_score(cycle)

def cycle_deviation_score(cycle)

   deviation_score = 0.0
   count = 0.0

   0 ... cycle.size.each do |member|
     participant = AssignmentParticipant.find(cycle[member][0].id)
     total_score = participant.get_review_score
     deviation_score = deviation_score + (total_score - cycle[member][1]).abs
     count = count + 1.0
   end

   deviation_score = deviation_score / count unless count == 0.0
   deviation_score
 end

def compute_quiz_scores(scores)

def compute_quiz_scores(scores)

   total = 0
   if scores[:quiz][:scores][:avg]
     return scores[:quiz][:scores][:avg] * 100  / 100.to_f
   else
     return 0
   end
   return total
 end

def review_response_maps

def review_response_maps

     participant = Participant.find(id)
     team_id = TeamsUser.team_id(participant.parent_id, participant.user_id)
     ReviewResponseMap.where(reviewee_id: team_id, reviewed_object_id: assignment.id)
   end

def members

def members

   team.try :participants
 end

def get_hash(time_stamp)

def get_hash(time_stamp)

   # first generate a hash from the assignment name itself
   hash_data = Digest::SHA1.digest(self.assignment.name.to_s)

   # second generate a hash from the first hash plus the user name and time stamp
   sign = hash_data + self.user.name.to_s + time_stamp.strftime("%Y-%m-%d %H:%M:%S")
   Digest::SHA1.digest(sign)
 end

Review methods

• The bookmark_reviews() method from AssignmentParticipant model have been moved to the BookmarkRatingQuestionnaire class.

def get_assessments_for(participant)

   BookmarkRatingResponseMap.get_assessments_for(participant) # participant.bookmark_reviews()
 end

• The teammmate_reviews() method from AssignmentParticipant model have been moved to the TeammateReviewQuestionnaire class.

def get_assessments_for(participant)

   TeammateReviewResponseMap.get_assessments_for(participant)   #participant.teammate_reviews()
 end

Testing

Please follow the below instruction to test UI:

• Login to Expertiza on http://152.46.20.199:3000/.
• Enter username as 'student13' and password as 'password'.
• You can select a previous assignment 'shivam test' or 'Pankti test'.
• You should be able to access the pages further
  • Your team- The page content should be visible without any errors.
  • Your work - The upload button for submission should be visible.
  • Your scores- The page should give result 0 and not any error.

When the user runs the application, the behavior of the application remains the same.

The existing RSpec test cases remain successful. The same can be checked by running Rspec spec The participant is able to log in to the system, view the assignments, submit links and files in assignment submission, view the scores, review peers, etc. Below are some of the execution screenshots after the refactoring of the model.

The Expertiza Login Screen

User can see all the assignments as below.

View team members for the assignment selected. In this case, we have taken a dummy assignment we created.

View the submission page to upload the assignment.

View the scores of an assignment.

Resources

1. Expertiza Github repository[2]
2. Our Github Repository[3]

References

<references/>