Nell Watson

The Usefulness of Chatbots

August 5, 2017 · 5 mins

Fools readily declare themselves by opening their mouths

Editorial note (2026): this essay describes the state of the art at the time of writing, when generative techniques were still largely pre-commercial and retrieval methods carried most working systems. The closing paragraph gives the 2026 position; the analysis below is preserved as written.

There has been a lot of discussion of chatbots recently, thanks to technological advances in Natural Language Processing and Deep Learning. However, there are still a great many limitations and caveats, and the experience of interaction with bots outside of a narrow context can often be underwhelming.

Chatbots can use a repository of predefined responses, and can attempt to choose an appropriate response based upon analysis of input and context. This pattern matching retrieval method is limited to the contents of its corpus of interactions. 

Generative conversational models however are capable of creating original content organically. These are based upon technology developed for machine translation, in order to better cope with situations where the meaning of a colloquial phrase may be figurative instead of literal. However, the translation is between an input and output, rather than languages. Such systems are generally more able to understand the semantic similarities between the questions such as 'what age are you?', and 'how old are you?'

Generative techniques are much more challenging, and are not yet in general commercial deployment, though generative techniques are the main focus of current research. They require huge amounts of training data. 

Retrieval methods are easier to develop, and though less sophisticated in the range of potential responses, they are less likely to make grammatical errors. However, retrieval methods cannot follow the context of a conversation easily, or refer back to previously mentioned information, or recall physical and demographic context of the conversation partner.

Chatbots are also challenged differently by the length and scope of a conversation. Generally, the longer a conversation continues, the greater likelihood of it breaking down. Longer conversations also require more info to be remembered from earlier, or even from previous sessions. Customer support typically involves long, branching conversations, whereas fast commercial interactions may require only one or two messages.

The scope or domain of a conversation may be limited to a particular task or topic, or may be broader or open, where there is no particular goal or intention. Taking a conversation in potentially any direction (open domain) is naturally very challenging. Generally commercial chatbots are focussed exclusively on providing assistive interactions in a narrowly defined area.

Personality is another aspect, whereby conversational choices may be weighted according to virtual personality vectors, such as agreeableness or openness to experience. This is still a very experimental area, and there is not much sophistication in these processes at present, particularly as training data is normally compiled from a wide range of human personalities.

Conversation length against conversation domain, and the technique each quadrant demands A two-by-two grid. The horizontal axis is conversation length, from short to long; the vertical axis is conversation domain, from closed at the bottom to open at the top. The short and closed quadrant is highlighted: fast commercial interactions of one or two messages in a narrowly defined area, where retrieval methods are enough. Long and closed holds customer support, with long branching conversations that retrieval cannot follow, because it cannot refer back to what was said earlier. Short and open is challenging because retrieval is limited to the contents of its corpus. Long and open, at top right, carries both difficulties at once and is marked as the hardest corner. Retrieval is viable in the short and closed quadrant only; every other quadrant demands generative techniques. LENGTH AGAINST DOMAIN, AND THE TECHNIQUE EACH QUADRANT DEMANDS Short and open No particular goal or intention. Taking a conversation in potentially any direction is naturally very challenging. Retrieval is limited to the contents of its corpus of interactions. Long and open Both difficulties at once: information to be remembered from earlier, and no bound on where the conversation may go. Generative territory: context-following, and huge amounts of training data. RETRIEVAL IS VIABLE IN THIS QUADRANT ONLY Short and closed Fast commercial interactions may require only one or two messages. Commercial bots focus exclusively on assistive interactions in a narrowly defined area. Retrieval is enough here. Long and closed Customer support typically involves long, branching conversations. The longer a conversation continues, the greater the likelihood of it breaking down. Retrieval cannot follow context or refer back to what was mentioned earlier. CLOSED OPEN CONVERSATION DOMAIN SHORT LONG CONVERSATION LENGTH
Chatbots are useful tools when applied in a short conversation of limited scope, and that is the one quadrant retrieval can serve. Length and domain are separate difficulties: the longer a conversation runs the likelier it is to break down, and taking it in potentially any direction is naturally very challenging. Retrieval methods are safer on grammar but limited to their corpus, and they cannot follow context or refer back to earlier information, so every quadrant except the bottom-left one demands generative techniques.

Replika has an approach that is somewhat different, in that they are attempting to collate a variety of information from a single user, in order to generate a virtual personality based upon conversation style and typical vocabulary. However, it is possible to compile a virtual personality from information created by a person who is now deceased, creating a digital echo of them that one may yet converse with. The balance of benefits and harms in such uses of the technology is open to interpretation and remains controversial. On one hand, having a virtual avatar of a loved one could assist with the grieving process as one learns to let go, on the other it could lead to complications or obsessions for some people.

In conclusion, chatbots are useful tools when applied in a short conversation of limited scope. By 2026, large language models can sustain broad, multi-turn conversations without establishing artificial general intelligence, though reliability, memory, and safety limitations remain. Some of the latest developments in areas such as Generative Conversational Models may lead to some exciting developments towards this in the mid-future however.

Technology

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