. 2017 Nov 16;19(11):e383. doi: 10.2196/jmir.7351

Table 2.

Themes on supportive embodied conversational agents.

Theme	Explanation	Sources
1. Computers as social actors	Humans treat media in the same way as they treat other humans.	Systematic search: [23] Hand search: [48-51] (concept=relationship)
2. Open dialogue between user and computer	Embodied conversational agents (ECAs) have the ability to have an open verbal dialogue with users.	Systematic search: [22] Hand search: [52-54] (concept=multimedia)
3. Visible conversational partner	Interaction with a “talking face” leads to more trust and believability.	Systematic search: [18,20,23,24] Hand search: [55-65] (concept=multimedia)
4. Human-ECA relationship	Interactions with an agent can lead to a relationship, which is important to keep users engaged over time.	Systematic search: [25] Hand search: [17,66-72] (concept=relationship)
5. Measures of the human-ECA relationship	Human-ECA relationship quality can be measured.	Systematic search: [17,21,68,73] (concept=relationship)
6. Responsive verbal and nonverbal communication	Computers should have the ability to notice and respond to verbally and nonverbally expressed emotions from their user to create a more natural interaction.	Systematic search: [23] Hand search: [63,74-81] (concept=relationship)
7. Impact of ECAs on user motivation	There is evidence that ECAs can motivate users, which is highly dependent on ECA implementation, context, task, etc.	Systematic search: [19] Hand search: [57,74,82-84] (concept=useful for eHealth^a)
8. Methodological issues within ECA research	Most experiments into ECAs face similar methodological issues, which have to be taken into account when interpreting the research.	Hand search: [85-89] (concept=useful for eHealth^a)

^aeHealth: electronic health.