Definition of Creativity

• Definition 1: "Creativity is what happens when an individual produces something that is novel as well as appropriate, generative or influential."
• Definition 2: "Creativity is the production of a novel and appropriate response, product, or solution to an open-ended task. Although the response must be new, it cannot be merely different; the nonsensical speech of a schizophrenic may be novel, but few would consider it creative. Thus, the response must also be appropriate to the task to be completed or the problem to be solved; that is, it must be valuable, correct, feasible, or somehow fitting to a particular goal. Moreover, the task must be open-ended (heuristic), rather than having a single, obvious solution (purely algorithmic). Ultimately, a response or product is creative to the extent that it is seen as creative by people familiar with the domain in which it was produced."
• Definition 3: “Creativity is the ability to produce work that is both novel (i.e. original, unexpected) and appropriate (i.e. useful concerning tasks constrains)”.

Measurement of Creativity

• A common measurement of creativity is done through an activity called the “unusual uses task.” This consists in asking participants to find as many ways to use a brick or a milk carton as possible. However, not all researchers agree with the efficiency of this test.
• Another common way to test creativity is self-report, by asking a subject to provide a list of his achievements. 
•  The Torrance Test of Creative Thinking is also used to test for creativity, it consists in giving the participants a figure that is incomplete which they have to draw and build an object upon.

Scholarly articles, papers, research projects, and books to read

• The Definition and Measurement of Creativity: What Do We Know? by Jaafar El-Murad and Douglas C. West, published in Volume 44, Issue 2 of the Journal of Advertising Research.
• The Handbook of Creativity, by Robert J. Sternberg, published by Cambridge University Press, 28 oct. 1998.
• The Measurement of Creativity: From Definitional Consensus to the Introduction of a New Heuristic Framework , by Mark Batey, published in The Creativity Research Journal in 2012.

Noteworthy people who speak and teach (or spoke and taught) on creativity

•  Teresa Amabile , a Baker Foundation Professor at Harvard Business School, with a Phd in psychology from Stanford University. Teresa spent her career researching creativity at work. She has written countless publications on the subject, as well as giving talks and videos. 
•  Marjorie Taylor, Professor Emerita at the University of Oregon, whose field of study is the development of imagination and creativity.
• E. Paul Torrance, a psychologist known as the father of creativity research.
•  Eric Maisel is a creativity coach who is available to give creativity coaching trainings.
•  Mark McGuinness is another creativity coach with 21 years of experience.