  We present the first systematic analysis of personality dimensions developed
specifically to describe the personality of speech-based conversational agents.
Following the psycholexical approach from psychology, we first report on a new
multi-method approach to collect potentially descriptive adjectives from 1) a
free description task in an online survey (228 unique descriptors), 2) an
interaction task in the lab (176 unique descriptors), and 3) a text analysis of
30,000 online reviews of conversational agents (Alexa, Google Assistant,
Cortana) (383 unique descriptors). We aggregate the results into a set of 349
adjectives, which are then rated by 744 people in an online survey. A factor
analysis reveals that the commonly used Big Five model for human personality
does not adequately describe agent personality. As an initial step to
developing a personality model, we propose alternative dimensions and discuss
implications for the design of agent personalities, personality-aware
personalisation, and future research.
