View source for CSC/ECE 517 Fall 2017/E17A0 Team-based reviewing

==='''Introduction'''===
==Motivation==
Traditionally, only individuals have been able to perform assignment reviews in Expertiza. Over the years, it has been observed that it would be more desirable if assignment setters could define how a specific assignment could be reviewed. One of the ways will be by an individual, and a new way of reviews will be by teams. The same teams formed for the assignment would be able to participate in reviewing peer assignments.

The benefits of peers review are numerous, and there is an additional benefit of reviews by teams. In general, we may be getting to a point where traditional individual reviews are becoming ineffective, often missing nuances in an assignments details and concepts. It is a general belief that team-based reviews will address this, often pooling together resources from multiple reviewers working as a team to form a one cohesive and often comprehensive review. On the flip-side, it may be difficult sometimes for all team members to meet to perform reviews, and this may either delay reviews or curtail them. Ultimately, it is felt that the advantages of team-based reviews far outweigh any inherent shortcomings.

==Changes to be Implemented==
1. A new button to select Reviewers as a team will be provided at the Assignments Edit page in the Review Strategy tab for the instructors<br>

2. Any member of a team should be able to select a review to be done by their team.<br>

3. Team members should not be allowed to edit a review simultaneously.<br>

4. The responses as well as the response_maps in the database should be deleted when the instructor decides to the change the 'Review Strategy' after the reviews have already started. <br>

In summary, functionality should be provided to allow Team reviews by connecting everything as mentioned above.<br>

==Database Migrations==
We will add the following fields in various existing models of the Expertiza.

1. To assign team based reviewing attribute to the assignemnts a new boolean field reviewer_is_team was added to the with the default set to false.

2. To create a common response for all the team members we added a team_id field to the ResponseMap model. This identifies the reviewer team.

3. To prevent concurrent editing of the reviews by the team members we lock the response in the ResponseMap. This is check is based on the new is_locked field.

4. To identify the user who has locked the review we have also added a locked_by field in the ResponseMap which carries the current_user.id.   

In summary, functionality should be provided to allow Team reviews by connecting everything as mentioned above.<br>

==Approach==
1. The first change is a simple view change. The checkbox will added in "assignments/edit/_review_strategy.html.erb". The checkbox value will be passed to the response_controller and depending on the value of the checkbox, the response_map will be created. The default value for the checkbox is "false". Thus, it will not break any existing functionality.
<pre>
...
  <!--#E17A0 Allow reviews to be set to be reviewed by a team -->
  <tr id="reviewer_is_team">
    <td>
      <input name="assignment_form[assignment][reviewer_is_team]" type="hidden" value="false"/>
      <%= check_box_tag('assignment_form[assignment][reviewer_is_team]', 'true', @assignment_form.assignment.reviewer_is_team) %>
      <%= label_tag('assignment_form[assignment][reviewer_is_team]', 'Reviews are to be performed by teams.') %>
    </td>
  </tr>
...
</pre>
<br>

2. For this feature to work we must create correct mappings. In Expertiza, all reviewees are AssignmentTeams, even in a non-team assignment where each team consists of a single participant. However, with this project, ''reviewers'' can be either participants or teams. In our design we are creating only one ResponseMap per team, i.e if the "reviewer_is_team" is set by the instructor, the ResponseMap created will have the reviewer_id as the participant_id of the requesting student and the team_id as the id of requesting students team in that assignment. Now to map this single response to all students in a team, we changed the strategy which returns response_mappings, in the "student_review_controller", for a particular reviewer. If the assignment has team_reviewers, then we find the responses by "team_id", and if there are no team reviewers for the assignment then we return responses by matching the "reviewer_id". Thus, if our mappings are created correctly, then the entire team will be directed to a single response_map and thus a single response irrespective of who requests the review. Thus, any of the team members will be able to request reviews as as the mappings will created with the team_id. The reason for us to not set the "reviewer_id" null or 0 for team reviewers is that, some of the functionalities like number of reviews, scores are all mapped to a single participant. Thus, if that is set that to any value, we will have to define all new methods for team reviewers. But, now we can use all those functions on our response and then make that same response object available to all members of the team. By doing this, we are neither creating redundant maps and nor are we defining new methods for the same functions. The code snippet below shows our new strategy to find the responses for a particular reviewer.
<pre>
...
    # E17A0 If an assignment is to be reviewed by a team, select it by team_id otherwise by reviewer_id
    if @reviewer_team_info[:reviewer_is_team_member]
      @review_mappings = ReviewResponseMap.where(team_id: @reviewer_team_info[:team_id])
      @team = Team.find(@reviewer_team_info[:team_id])
    else
      @review_mappings = ReviewResponseMap.where(reviewer_id: @participant.id)
    end
...
</pre>
<br>

3. This is an important feature since if we allow teammates to edit reviews concurrently, each of them will overwrite each other's changes. We have handled this by using the ''is_locked'' and ''locked_by'' field in the response_map table. Using these fields, we will lock the response for the current_user. Thus, when one teammate is editing, the response is locked and that members id is stored in the ''locked_by'' field. Now for other users we will check ''locked_by'' field. If it does not match their id then they will not see the ''edit'' button on the reviews page.
This response is then unlocked when the current_user saves the response. The methods for locking and unlocking the response are defined in the
<pre>
...
  #E17A0 Lock response
  def lock_response_map response_id
    review_response_map = ReviewResponseMap.find_by_id(Response.find(response_id).map_id)
    unless review_response_map.nil?
      ReviewResponseMap.update(review_response_map.id, :is_locked => true, :locked_by => current_user.id)
    end
  end
  
  #E17A0 Unlock Response
  def unlock_response_map response_id
    review_response_map = ReviewResponseMap.find_by_id(response_id)
    unless review_response_map.nil?
      ReviewResponseMap.update(review_response_map.id, :is_locked => false, :locked_by => current_user.id)
    end
  end
...
</pre>

4/5. Changes 4 and 5 are both database migrations. Thus, we just add these fields in their respective tables.

6. This feature is provided to handle a rare edge case. Say that the instructor decides to change the review strategy after the reviews have already started. Now, the format of the response_maps already created will not match the response_maps that will be created after the strategy change. Thus, if the instructor wants to change the strategy, s/he can delete all reviews already done, and then instruct students to start over. The ''delete_reviews'' method is defined in the ''assignment'' model. Our method deletes all the response_maps as well as all the response objects created.
<pre>
...
  def delete_reviews
    responsemap = ResponseMap.where(reviewed_object_id: self.id, type: 'ReviewResponseMap')
    response = Response.where(map_id: responsemap.ids)
    response.each { |r| Answer.destroy_all(response_id: r.id)}
    Response.destroy_all(map_id: responsemap.ids)
    ResponseMap.destroy_all(id: responsemap.ids)
  end
...
</pre>

==Files Involved==
1. response_map.rb

2. assignment.rb

3. response_controller.rb

4. review_mapping_controller.rb

5. assignments/edit/_review_strategy.html.erb

==Design Principles to be Followed==
1. MVC - The project is implemented in Ruby on Rails that uses MVC architecture. It separates an application’s data model, user interface, and control logic into three distinct components (model, view, and controller, respectively).<br>

2. DRY Principle - We are trying to reuse the existing functionalities in Expertiza, thus avoiding code duplication. Whenever possible, code modification based on the existing classes, controllers, or tables will be done instead of creating the new one.<br>

3. Polymorphism - We will use polymorphism to provide a single interface to entities of different types. In Expertiza, individual and team-based reviewers will share one single interface.<br>

==Use Case==

<div  style="padding: 0px 0px 0px 25px">
[[File:UC_new.png|none]]
</div>

1. Name: Teams submitting reviews for assignment or topic

2. Actor: Student (as member of a team)

3. Other Participants: Team Members

4. Precondition: Instructor has set up an assignment with review strategy as "Team Reviews". This assignment also has only teams. No students can participate as an individual. Thus, when a participant is added to the assignment, s/he will be added as a single member team. Thus, in the diagram above, the participant is a single member team. 

5. Primary Sequence:
<li> Log in to Expertiza.
<li> Select an assignment.
<li> Select "other's work".
<li> The student can request a review for the team from here.
<li> Depending on the number of reviews allowed and the number of reviews already performed by the team, they will be allotted a new review
<li> Begin the review.
<li> Only one member of the team can edit the review at an given time.
<li> All restrictions that apply to individual reviewers, also apply to teams (e.g. like a individual reviewer, a team also cannot have more than 2 outstanding incomplete reviews).
<li> Complete the review and Click Submit.
<br>

==UI Changes==
1. Currently there is no team reviewing in Expertiza. Thus, we will provide a check-box, in the review strategy tab of edit assignments, for the instructor. Checking this box will set the reviewers to teams, rather than individual participants.
<br>
'''Current Implementation is as follows:'''
<br>
<div  style="padding: 0px 0px 0px 25px">
[[File:Current_implementation1.png|none|frame]]
</div>

----

<br>
'''New Implementation will be as shown below:'''
<br>
<div  style="padding: 0px 0px 0px 25px">
[[File:Improved_syn_chkbox.png|none|frame]]
</div>
----

<br>
2. By default, the reviewers will be individual students. When they request reviews, they request reviews for themselves. If the instructor changes the reviewers to teams, then each participant (who is member of some team), will request reviews on behalf of the entire team.
<br>
'''If the assignment has individual reviews:'''
<br>
<div  style="padding: 0px 0px 0px 25px">
[[File:Student_review1.png|none|frame]]
</div>
----

<br>
'''If the assignment has team reviews:'''
<br>
<div  style="padding: 0px 0px 0px 25px">
[[File:Improved_review_req.png|none|frame]]
</div>
----

<br>

Select a new submission for your team to review.

==Test Plan==
The Assignments functions; including creation, updating, saving and modifying methods have already been tested, and our test plan will only deal with testing for the new team-based reviewing functionality we are adding. Our test plan will include the following test methods:<br>

1. If the review for the Assignment will have team id instead of the participant id in Response Map.<br>

2. If for an assignment the instructor can successfully apply the reviewer_is_team? attribute.<br>

3. If while a review is being edited by a team member, the other team members should not be given access to edit the same review.<br>

4. If the team based reviewing functionality works in flow with the student based reviewing.<br>

==Team Information==
[mailto:ashah22@ncsu.edu Aditya Shah]<br>
[mailto:adeshmu@ncsu.edu Amey Deshmukh]<br>
[mailto:dkalro@ncsu.edu Deepak Kalro]<br>
[mailto:pmusyok@ncsu.edu Philip Musyoki]
----