Effectiveness is the capability of producing a desired result. When something is deemed effective, it means it has an intended or expected outcome, or produces a deep, vivid impression.

The origin of the word "effective" stems from the Latin word effectīvus, which means creative, productive or effective. It surfaced in Middle English between 1300-1400 A.D.

In mathematics, effective is sometimes used as a synonym of algorithmically computable.

In physics, an effective theory is, similar to a phenomenological theory, a framework intended to explain certain (observed) effects without the claim that the theory correctly models the underlying (unobserved) processes.

In heat transfer, effectiveness is a measure of the performance of a heat exchanger when using the NTU method.

In medicine, effectiveness relates to how well a treatment works in practice, as opposed to efficacy, which measures how well it works in clinical trials or laboratory studies.

In management, effectiveness relates to getting the right things done. Peter Drucker reminds us that effectiveness can and must be learned.”.

Peter Albert David Singer (born 6 July 1946) is an Australian philosopher who is the Ira W. DeCamp Professor of Bioethics at Princeton University and Laureate Professor at the Centre for Applied Philosophy and Public Ethics at the University of Melbourne. He specialises in applied ethics and approaches ethical issues from a secular, preference utilitarian perspective.

He has served, on two occasions, as chair of philosophy at Monash University, where he founded its Centre for Human Bioethics. In 1996, he unsuccessfully stood as a Greens candidate for the Australian Senate. In 2004, he was recognised as the Australian Humanist of the Year by the Council of Australian Humanist Societies. He has been voted one of Australia's ten most influential public intellectuals. Singer serves on the Advisory Board of Incentives for Global Health, the NGO formed to develop the Health Impact Fund proposal.

Outside academic circles, Singer is best known for his book Animal Liberation, widely regarded as the touchstone of the animal liberation movement. Not all members of the animal liberation movement share this view, and Singer himself has said the media overstates his status. His views on that and other issues in bioethics have attracted attention and a degree of controversy.

Stephen Richards Covey (born October 24, 1932 in Salt Lake City, Utah) is the author of the best-selling book, The Seven Habits of Highly Effective People. Other books he has written include First Things First, Principle-Centered Leadership, and The Seven Habits of Highly Effective Families. In 2004, Covey released The 8th Habit. In 2008, Covey released The Leader In Me—How Schools and Parents Around the World Are Inspiring Greatness, One Child at a Time. He is a professor at the Jon M. Huntsman School of Business at Utah State University.

Covey is the son of Stephen Glenn Covey and his wife Irene Louise Richards. Louise is the daughter of Stephen L Richards, an apostle and counselor in the first presidency of the Church of Jesus Christ of Latter-day Saints under David O. McKay.^{[citation needed]}

Covey earned a B.S. in business administration from the University of Utah, an MBA from Harvard University, and a Doctor of Religious Education (DRE) from Brigham Young University. Covey is a brother of Pi Kappa Alpha International Fraternity. He has been awarded ten honorary doctorates.