University of California
Supply
This site provides an explanation of the difference between a change in supply and a change in quantity supplied, terms which many economics students confuse.
University of Notre Dame
Economics 504: Chapter 3: Problems
Dr. Wilber's website offers an analysis of the differences between a "change in supply" vs. a "change in quantity supplied," and provides some sample questions along with answers.
Robert Schenk, PhD
Supply Terminology
This site briefly discusses the difference between a "change in supply" vs. a "change in quantity supplied."
Curated OER
Supply Curve
This site shows the relationship between price and quantity supplied, and why the relationship between price and quantity is positive or direct.