Fact: Trial and Error is the fundamental way of solving problems. 

2. Trial and Error's positive attribute is to not know anything about the subject and figuring out the solution. 

3. Trial and Error's negative attribute is work-intensive. 

4. Trial and Error's positive attribute is to 100% figure out the solution where time is not limited. 

5. Trial and Error also works for every person regardless of IQ. 

Diagram:  

Risks: Time involved is extensive. 

Conclusion: Trial and Error is one of the most fundamental way to solve problems, it is suitable for everyone to figure out products and solutions.