Answer the following questions attached. Any references used, should be APA format. No specific words required.

Answer the following questions. Any references used, should be APA format. No specific words required.

RESEARCH METHODS IN APPLIED SETTINGS

1. Shadish, Cook and Campbell proposed a long list of threats to research validity. Explore the difference between the threats of History vs. the threats of Maturation? 

2. Explore the difference between probability sampling and nonprobability sampling?