Chemistry Nobel Laureate Martin Chalfie explains the origin of impact factors and the problem with the way we use them.

Dr Chalfie visited Brazil from 2426 September 2014, as part of the Nobel Prize Inspiration Initiative. Through the Initiative, Nobel Laureates give career advice for young scientists, explain their discoveries and give insights into life after the Nobel Prize.

See http://www.nobelprizeii.org/ for more advice from Nobel Laureates, or subscribe to the Nobel Prize Inspiration Initiative YouTube channel.

Watch our YouTube playlist to hear other Nobel Laureates’ views on impact factors:    • What do Nobel Laureates think of impa...