Last week, we learned about the internal and external validity of a study. This

Last week, we learned about the internal and external validity of a study. This week we read about the validity of measures.
How is this different? What is the validity of a measure and how can this be assessed?
This week we also read about the reliability of a measure.
What is the reliability of a measure and how is this assessed?
What is the relationship between the reliability and validity of a measure?
Make sure to clearly define all terms and use examples, when appropriate, to illustrate your understanding of the material. As always, use APA-style citations and references for your work.