Click on the following links. Please note these will open in a new window.

Video Links

Scales of Measurement 
Description: This YouTube video uses an example to illustrate what variables are and the four scales of measurement (nominal, ordinal, interval, ratio). 

Reliability 
Description: The video describes the concept of reliability and the various types of reliability.

Audio Links

The Hawthorne Effect 
Description: The BBC Radio audio link examines the origins of the psychological effect known as participant reactivity, more commonly known as the Hawthorne effect, based on the factory productivity experiments conducted in the 1920s.

Web Resources

Validity 
Description: This York University website delineates the types of validity in psychological tests as well as the appropriate tests of determining validity

Measurement: Reliability and Validity
Description: This excellent PDF gives an overview of important terms such as levels of measurement, reliability and validity of measurement, and how to evaluate reliability and validity.