Coursera:
Advantages: 
1. Offers courses from top universities and industry leaders
2. Provides regular assessments and peer-reviews
3. Allows users to interact directly with professors

Disadvantages:
1. Course materials can be expensive 
2. Not all courses require certification
3. Technical requirements for access to some courses 

Udemy:
Advantages: 
1. More affordable than Coursera
2. Some courses offer certification after completion
3. Can access course materials anytime and anywhere 

Disadvantages:
1. Quality of courses can be lacking
2. Fewer courses than Coursera 
3. Little to no assessment or peer review
Help the user decide which online course platform to use by providing three advantages and three disadvantages for each platform.
Platforms: Coursera and Udemy