A virtual assistant or intelligent personal assistant is a software agent that can perform tasks or services for an individual. Sometimes the term "chatbot" is used to refer to virtual assistants generally or specifically those accessed by online chat (or in some cases online chat programs that are for entertainment and not useful purposes). Some virtual assistants are able to interpret human speech and respond via synthesized voices. Users can ask their assistants questions, control home automation devices and media playback via voice, and manage other basic tasks such as email, to-do lists, and calendars with verbal commands. 
As of 2017, the capabilities and usage of virtual assistants are expanding rapidly, with new products entering the market and a strong emphasis on voice user interfaces. Apple and Google have large installed bases of users on smartphones. Microsoft has a large installed base of Windows-based personal computers, smartphones and smart speakers. Alexa has a large install base for smart speakers.
The first tool enabled to perform digital speech recognition was the IBM Shoebox, presented to the general public during the 1962 Seattle World's Fair after its initial market launch in 1961. This early computer, developed almost 20 years before the introduction of the first IBM Personal Computer in 1981, was able to recognize 16 spoken words and the digits 0 to 9. The next milestone in the development of voice recognition technology was achieved in the 1970s at the Carnegie Mellon University in Pittsburgh, Pennsylvania with substantial support of the United States Department of Defense and its DARPA agency. Their tool "Harpy" mastered about 1000 words, the vocabulary of a three-year-old. About ten years later the same group of scientists developed a system that could analyze not only individual words but entire word sequences enabled by a Hidden Markov Model. Thus, the earliest virtual assistants, which applied speech recognition software were automated attendant and medical digital dictation software. In the 1990s digital speech recognition technology became a feature of the personal computer with Microsoft, IBM, Philips and Lernout & Hauspie fighting for customers. Much later the market launch of the first smartphone IBM Simon in 1994 laid the foundation for smart virtual assistants as we know them today. The first modern digital virtual assistant installed on a smartphone was Siri, which was introduced as a feature of the iPhone 4S on October 4, 2011. Apple Inc. developed Siri following the 2010 acquisition of Siri Inc., a spin-off of SRI International, which is a research institute financed by DARPA and the United States Department of Defense.
Method of interaction
Virtual assistants make work via:
- Text (online chat), especially in an instant messaging app or other app
- Voice, for example with Amazon Alexa on the Amazon Echo device, Siri on an iPhone, or Google Assistant on Google-enabled/Android mobile devices
- By taking and/or uploading images, as in the case of Samsung Bixby on the Samsung Galaxy S8
Virtual assistants use natural language processing (NLP) to match user text or voice input to executable commands. Many continually learn using artificial intelligence techniques including machine learning.
To activate a virtual assistant using the voice, a wake word might be used. This is a word or groups of words such as "Hey Mycroft", "Alexa", "Hey Siri" or "OK Google".
Devices and objects where found
Virtual assistants may be integrated into many types of platforms or, like Amazon Alexa, across several of them:
- Into devices like smart speakers such as Amazon Echo, Google Home and Apple HomePod
- In instant messaging apps on both smartphones and via the Web, e.g. Facebook's M (virtual assistant) on both Facebook and Facebook Messenger apps or via the Web
- Built into a mobile operating system (OS), as are Apple's Siri on iOS devices and BlackBerry Assistant on BlackBerry 10 devices, or into a desktop OS such as Cortana on Microsoft Windows OS
- Built into a smartphone independent of the OS, as is Bixby on the Samsung Galaxy S8 and Note 8.
- On other mobile apps such as Google Allo
- Within instant messaging platforms, assistants from specific organizations, such as Aeromexico's Aerobot on Facebook Messenger or Wechat Secretary on WeChat
- Within mobile apps from specific companies and other organizations, such as Dom from Domino's Pizza
- On smartwatches
- In appliances, cars, and Android Wear clothing.
- Previous generations of virtual assistants often worked on websites, such as Alaska Airlines' Ask Jenn, or on interactive voice response (IVR) systems such as American Airlines' IVR by Nuance.
- Orange Djingo
Virtual assistants can provide a wide variety of services, and particularly those from Amazon Alexa and Google Assistant grow by the day. These include:
- Provide information such as weather, facts from e.g. Wikipedia or IMDB, set an alarm, make to-do lists and shopping lists
- Play music from streaming services such as Spotify and Pandora; play radio stations; read audiobooks
- Play videos, TV shows or movies on televisions, streaming from e.g. Netflix
- Conversational commerce (see below)
- Assist public interactions with government (see Artificial intelligence in government)
- Complement and/or replace customer service by humans. One report estimated that an automated online assistant produced a 30% decrease in the work-load for a human-provided call centre.
Conversational commerce is e-commerce via various means of messaging, including via voice assistants but also live chat on e-commerce Web sites, live chat on messaging apps such as WeChat, Facebook Messenger and WhatsApp and chatbots on messaging apps or Web sites.
Amazon enables Alexa "Skills" and Google "Actions", essentially apps that run on the assistant platforms.
Virtual assistant privacy
Virtual assistants have a variety of privacy concerns associated with them. Features such as "Hey Siri" pose a threat, as such features are always listening.  However, such features are important to make devices accessible for people who may otherwise have trouble.  Modes of privacy such as the virtual security button have been proposed to create a multilayer authentication for virtual assistants. 
The platforms that power the most widely used virtual assistants are also used to power other solutions:
- Amazon Lex was opened to developers in April 2017. It involves natural language understanding technology combined with automatic speech recognition and had been introduced in November 2016.
- Google provides the Actions on Google and Dialogflow platforms for developers to create "Actions" for Google Assistant
- Apple provides SiriKit for developers to create extensions for Siri
- IBM's Watson, while sometimes spoken of as a virtual assistant is in fact an entire artificial intelligence platform and community powering some virtual assistants, chatbots. and many other types of solutions.
In previous generations of text chat-based virtual assistants, the assistant was often represented by an avatar of (a.k.a. 'interactive online character or automated character) — this was known as an embodied agent.
Full comparison of assistants
|Intelligent personal assistant||Developer||Free software||Free and open-source hardware||HDMI out||External I/O||IOT||Chromecast integration||Smart phone app||Always on||Unit to unit voice channel|
|Alexa (a.k.a. Echo)||Amazon.com||No||No||No||No||Yes||No||Yes||Yes||?|
|BlackBerry Assistant||BlackBerry Limited||No||N/A||N/A||N/A||No||No||Yes||No||N/A|
|Evi||Amazon.com True Knowledge||No||N/A||N/A||N/A||No||No||Yes||No||N/A|
|M (discontinued January 2018)|
|Lucida||Clarity Lab, University of Michigan
[third-party source needed]
|Saiy(a.k.a. utter!)||Saiy Ltd.||Yes||N/A||N/A||N/A||N/A||N/A||Yes||Yes||N/A|
|Sherpa||Sherpa Europe SL||No||N/A||N/A||N/A||Yes||No||Yes||Yes||N/A|
|Viv (a.k.a. Bixby)||Samsung Electronics||No||N/A||N/A||N/A||Yes||No||Yes||No||N/A|
Digital experiences enabled by virtual assistants are considered to be among the major recent technological advances and most promising consumer trends. Experts claim that digital experiences will achieve a status-weight comparable to ‘real’ experiences, if not become more sought-after and prized. The trend is verified by a high number of frequent users and the substantial growth of worldwide user numbers of virtual digital assistants. In mid-2017, the number of frequent users of digital virtual assistants is estimated to be around 1bn worldwide. In addition, it can be observed that virtual digital assistant technology is no longer restricted to smartphone applications, but present across many industry sectors (incl. automotive, telecommunications, retail, healthcare and education). In response to the significant R&D expenses of firms across all sectors and an increasing implementation of mobile devices, the market for speech recognition technology is predicted to grow at a CAGR of 34.9% globally over the period of 2016 to 2024 and thereby surpass a global market size of USD 7.5 billion by 2024. According to an Ovum study, the "native digital assistant installed base" is projected to exceed the world's population by 2021, with 7.5 billion active voice AI–capable devices.  According to Ovum, by that time "Google Assistant will dominate the voice AI–capable device market with 23.3% market share, followed by Samsung's Bixby (14.5%), Apple's Siri (13.1%), Amazon's Alexa (3.9%), and Microsoft's Cortana (2.3%)."
Taking into consideration the regional distribution of market leaders, North American companies (e.g. Nuance Communications, IBM, eGain) are expected to dominate the industry over the next years, due to the significant impact of BYOD (Bring Your Own Device) and enterprise mobility business models. Furthermore, the increasing demand for smartphone-assisted platforms are expected to further boost the North American Intelligent Virtual Assistant (IVA) industry growth. Despite its smaller size in comparison to the North American market, the intelligent virtual assistant industry from the Asia-Pacific region, with its main players located in India and China is predicted to grow at an annual growth rate of 40% (above global average) over the 2016-2024 period.
In May 2018, researchers from the University of California, Berkeley, published a paper that showed audio commands undetectable for the human ear could be directly embedded into music or spoken text, thereby manipulating virtual assistants into performing certain actions without the user taking note of it. The researchers made small changes to audio files, which cancelled out the sound patterns that speech recognition systems are meant to detect. These were replaced with sounds that would be interpreted differently by the system and command it to dial phone numbers, open websites or even transfer money. The possibility of this has been known since 2016, and affects devices from Apple, Amazon and Google.
In addition to unintentional actions and voice recording, another security and privacy risk associated with intelligent virtual assistants is malicious voice commands: An attacker who impersonates a user and issues malicious voice commands to, for example, unlock a smart door to gain unauthorized entry to a home or garage or order items online without the user's knowledge. Although some IVAs provide a voice-training feature to prevent such impersonation, it can be difficult for the system to distinguish between similar voices. Thus, a malicious person who is able to access an IVA-enabled device might be able to fool the system into thinking that he or she is the real owner and carry out criminal or mischievous acts.
- Applications of artificial intelligence
- Computer facial animation
- Expert system
- Home network
- Intelligent agent
- Knowledge Navigator
- Microsoft Office Assistant
- Natural language processing
- Simulated reality
- Software agent
- Wizard (software)
- Hoy, Matthew B. (2018). "Alexa, Siri, Cortana, and More: An Introduction to Voice Assistants". Medical Reference Services Quarterly. 37 (1): 81–88. doi:10.1080/02763869.2018.1404391. PMID 29327988.
- Daniel B. Kline (2017-01-30). "Alexa, How Big Is Amazon's Echo?". The Motley Fool.
- "Feature: Von IBM Shoebox bis Siri: 50 Jahre Spracherkennung - WELT" [From IBM Shoebox to Siri: 50 years of speech recognition]. Die Welt (in German). Welt.de. 2012-04-20. Retrieved 2017-12-10.
- Zwass, Vladimir (2016-02-10). "speech recognition | technology". Encyclopædia Britannica Online. Britannica.com. Retrieved 2017-12-10.
- "Smartphone: your new personal assistant - Orange Pop". Pop.orange.com. 2016-02-23. Archived from the original on 2017-07-10. Retrieved 2017-12-10.
- Darren Murph (2011-10-04). "iPhone 4S hands-on!". Engadget.com. Retrieved 2017-12-10.
- "S7617 - Developing Your Own Wake Word Engine Just Like 'Alexa' and 'OK Google'". GPU Technology Conference. Retrieved July 17, 2017.
- Lynn La (2017-02-27). "Everything Google Assistant can do on the Pixel". CNET. Retrieved 2017-12-10.
- Morrison, Maureen (2014-10-05). "Domino's Pitches Voice-Ordering App in Fast-Food First | CMO Strategy". AdAge. Retrieved 2017-12-10.
- Dan O'Shea (2017-01-04). "LG introduces smart refrigerator with Amazon Alexa-enabled grocery ordering". Retail Dive. Retrieved 2017-12-10.
- Samuel Gibbs (2017-02-07). "Amazon's Alexa escapes the Echo and gets into cars | Technology". The Guardian. Retrieved 2017-12-10.
- "What is Google Assistant, how does it work, and which devices offer it?". Pocket-lint. 2017-10-06. Retrieved 2017-12-10.
- ""Ask Jenn", Alaska Airlines website". Alaskaair.com. 2017-01-02. Retrieved 2017-12-10.
- AT&T Tech Channel (2013-06-26). "American Airlines (US Airways) - First US Airline to Deploy Natural Language Speech" (video), Nuance Enterprise on YouTube. YouTube.com. Retrieved 2017-12-10.
YouTube title: Airline Information System, 1989 - AT&T Archives - speech recognition
- Sayer, Peter (April 20, 2017). "By Djingo, there's a new virtual assistant". PC World. IDG News Service. Retrieved July 20, 2017.
- Taylor Martin; David Priest (2017-09-10). "The complete list of Alexa commands so far". CNET. Retrieved 2017-12-10.
- Kongthon, Alisa; Sangkeettrakarn, Chatchawal; Kongyoung, Sarawoot; Haruechaiyasak, Choochart (2009-01-01). Implementing an Online Help Desk System Based on Conversational Agent. Proceedings of the International Conference on Management of Emergent Digital EcoSystems. MEDES '09. New York, NY, USA: ACM. pp. 69:450–69:451. doi:10.1145/1643823.1643908. ISBN 9781605588292.
- Anthony O'Donnell (2010-06-03). "Aetna's new "virtual online assistant"". Insurance & Technology. Archived from the original on 2010-06-07.
- "How to prepare your products and brand for conversational commerce". 6 March 2018.
- Taylor, Glenn. "Retail's Big Opportunity: 87% Of U.S. Consumers Grasp The Power Of Conversational Commerce - Retail TouchPoints".
- Zhang, Guoming; Yan, Chen; Ji, Xiaoyu; Zhang, Tianchen; Zhang, Taimin; Xu, Wenyuan (2017). "DolphinAttack". Proceedings of the 2017 ACM SIGSAC Conference on Computer and Communications Security - CCS '17. pp. 103–117. arXiv:1708.09537. doi:10.1145/3133956.3134052. ISBN 9781450349468.
- Lei, Xinyu; Tu, Guan-Hua; Liu, Alex X.; Li, Chi-Yu; Xie, Tian (2017). "The Insecurity of Home Digital Voice Assistants - Amazon Alexa as a Case Study". arXiv:1712.03327 [cs.CR].
- "Amazon Lex, the technology behind Alexa, opens up to developers". TechCrunch. 2017-04-20. Retrieved 2017-12-10.
- "Actions on Google | Google Developers". Retrieved 2017-12-10.
- "Watson - Stories of how AI and Watson are transforming business and our world". Ibm.com. Retrieved 2017-12-10.
- Memeti, Suejb; Pllana, Sabri (January 2018). "PAPA: A parallel programming assistant powered by IBM Watson cognitive computing technology". Journal of Computational Science. 26: 275–284. doi:10.1016/j.jocs.2018.01.001. Retrieved 16 February 2018.
- "Baidu unveils 3 smart speakers with its Duer digital assistant". 8 January 2018.
- Newton, Casey (14 January 2018). "Facebook is shutting down M, its personal assistant service that combined humans and AI". The Verge. Vox Media. Retrieved 8 January 2018.
- Janakiram MSV (20 August 2015). "Meet Mycroft, The Open Source Alternative To Amazon Echo". Forbes. Retrieved 27 October 2016.
- "5 Consumer Trends for 2017". TrendWatching. 2016-10-31. Retrieved 2017-12-10.
- Felix Richter (2016-08-26). "Chart: Digital Assistants - Always at Your Service". Statista. Retrieved 2017-12-10.
- "Virtual Assistant Industry Statistics « Global Market Insights, Inc". Gminsights.wordpress.com. 2017-01-30. Retrieved 2017-12-10.
- "Virtual digital assistants to overtake world population by 2021". ovum.informa.com. Retrieved 2018-05-11.
- "Alexa and Siri Can Hear This Hidden Command. You Can't". The New York Times. 2018-05-10. ISSN 0362-4331. Retrieved 2018-05-11.
- "As voice assistants go mainstream, researchers warn of vulnerabilities". CNET. 2018-05-10. Retrieved 2018-05-11.
- Chung, H.; Iorga, M.; Voas, J.; Lee, S. (2017). "Alexa, Can I Trust You?". Computer. 50 (9): 100–104. doi:10.1109/MC.2017.3571053. ISSN 0018-9162. PMC 5714311. PMID 29213147.