internal validity

1.    Definitions& Terms from the Chapters
a.    Briefly define and state the purpose of experimental research.
b.    Briefly define single subject experimental research designs and explain why they might be used instead of a group experimental research design.
c.    Describe what is meant by the term “internal validity.”
d.    Describe what is meant by the term “external validity.”
e.    Define mixed methods research, and describe the purpose of a mixed methods study.
f.    State a definition and describe the purpose of action research