Click on the following links. Please note these will open in a new window.
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).
Description: The video describes the concept of reliability and the various types of reliability.
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.
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.