CSC/ECE 517 Spring 2016/Badging System

Introduction

Background

Much like physical badges in the army and youth scout troops, digital badges are an assessment and credentialing mechanism that is housed and managed online. Badges are designed to make visible and validate learning in both formal and informal settings, and hold the potential to help transform where and how learning is valued. In other words, badges may be used in order to set goals and motivations for students and reward and may help to improve their academic scores. Badges can also be considered as a way to reward student’s success. Moreover, badges can be used by teachers for alternative assessment techniques.

Purpose

One request for the Expertiza system is to add a badging system as a way to measure student performance. Expertiza will take advantage of the motivations created from badges by awarding students with new badges based off providing a variety of factors within the Expertiza system. Some of these badges include: achieving a top percentage of scores in an assignment, achieving a high peer review score, performing well overall in a course and other manual accomplishments deemed necessary by the teaching staff for a course. Instead of implementing the whole badging system, we will call an existing online badging web service, Credly, and integrate it with Expertiza.

Requirements

Use Case

The following simple illustration shows the use cases of the system.

Deciding External Web Service

Factors	Open Badges	Credly	Bestr
Native User Management	No	Yes. No need to store all records locally.	No
Extensive API Support	Yes. But many still in beta phase.	Yes. (Primary reason for choosing Credly)	No
Interactive Badge Builder SDK	Yes. But still in beta phase.	Yes	Yes. But gives few options for cusromization.
Existing Integration with other systems	Few	Many	No
Monetary Costs	Free	Free tier as well as paid plans.	Paid.

Database Design

The following tables will be created to implement a solution for this project. 1. badges table - which stores badge_id and their descriptions.

Column	Type	Comment
badge_id	int	Primary key. Auto-generated
name	string	Description of the badge

2. badge_users table - which stores details about what badges are assignment to a user and related details.

Column	Type	Comment
badge_id	int	Primary key. Auto-generated
user_id	int	Referenced from users table
course_id	int	Referenced from courses table
assignment_id	int	Referenced from assignments table
is_course_badge	boolean	Whether badge is a course-badge or individual-badge
strategy	string	Describes the strategy of awarding

3. badge_groups - which stores information about which badges should be assigned depending on the threshold score.

Column	Type	Comment
badge_id	int	Primary key. Auto-generated
strategy	string	Describes the strategy of awarding
threshold	int	Score required to award the badge

4. assignment_groups - which stores details about the team badges.

Column	Type	Comment
assignment_group_id	int	Primary key. Auto-generated
badge_group_id	int	Referenced from badge_groups table
assignment_id	int	Referenced from assignments table

Design Pattern

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).
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.

Object Oriented Design

As with most Ruby on Rails applications, this solution uses the Model-View-Controller design pattern. The following diagram shows a workflow of the planned design along with the attributes and operations that are relevant to the implementation of this solution.

Mockups

Mockup goes here