Weak artificial intelligence (weak AI), also known as narrow AI, is artificial intelligence that is focused on one narrow task. Weak AI is defined in contrast to strong AI, a machine with the ability to apply intelligence to any problem, rather than just one specific problem, sometimes considered to require consciousness, sentience and mind).. Many currently existing systems that claim to use "artificial intelligence" are likely operating as a weak AI focused on a narrowly defined specific problem.
Siri is a good example of narrow intelligence. Siri operates within a limited pre-defined range of functions. There is no genuine intelligence or no self-awareness despite being a sophisticated example of weak AI. Siri brings several narrow AI techniques to the capabilities of an iPhone.  AI researcher Ben Goertzel, on his blog in 2010, stated Siri was "VERY narrow and brittle" evidenced by annoying results if you ask questions outside the limits of the application.
Some commentators think weak AI could be dangerous because of this "brittleness" and fail in unpredictable ways. Weak AI could cause disruptions in the electric grid, damage nuclear power plants, cause global economic problems, and misdirect autonomous vehicles.  In 2010, weak AI trading algorithms led to a “flash crash,” causing a temporary but significant dip in the market.
- io9.com mentions narrow AI. Published 1 April 2013, retrieved 16 February 2014: http://io9.com/how-much-longer-before-our-first-ai-catastrophe-464043243
- AI researcher Ben Goertzel explains why he became interested in AGI instead of narrow AI. Published 18 Oct 2013. Retrieved 16 February 2014. http://intelligence.org/2013/10/18/ben-goertzel/
- TechCrunch discusses AI App building regarding Narrow AI. Published 16 Oct 2015, retrieved 17 Oct 2015. https://techcrunch.com/2015/10/15/machine-learning-its-the-hard-problems-that-are-valuable/
- Retrieved 16 February 2014. https://www.forbes.com/sites/tedgreenwald/2011/10/13/how-smart-machines-like-iphone-4s-are-quietly-changing-your-industry/
- Ben Goertzel blog-post retrieved 16 February 2014. Published 6 February 2010. http://multiverseaccordingtoben.blogspot.com/2010/02/siri-new-iphone-personal-assistant-some.html
- Retrieved 16 February 2014. http://io9.com/how-much-longer-before-our-first-ai-catastrophe-464043243
- Retrieved 16 February 2014. http://cyberlaw.stanford.edu/blog/2011/08/sorcerers-apprentice-or-why-weak-ai-interesting-enough