# Creation, Analysis and Evaluation of AnnoMI, a Dataset of Expert-Annotated Counselling Dialogues +
## 6 Dataset Analysis
### Posterior (Main) Behaviour and Talk Type Distributions  
MI guidelines have specific recommendations on how a therapist should respond when the client talks in certain ways, and a client may also react to the therapist in particular patterns. We therefore probe the posterior distributions of next-turn therapist behaviours (/client talk types) given the current-turn client talk type (/ therapist behaviour). Denoting \(u_{t}^{T}\) as the therapist utterance at turn (time step) \(t\) and \(u_{t+1}^{C}\) as the client reply in the following turn, the posterior distribution of client talk types can be represented as \(p(\textit{Talk\_Type}(u_{t+1}^{C})\mid\textit{Behaviour}(u_{t}^{T}))\). Similarly, the posterior distribution of therapist behaviours can be formulated as \(p(\textit{Behaviour}(u_{t+1}^{T})\mid\textit{Talk\_Type}(u_{t}^{C}))\)  
Figure 3 presents the posterior distribution of client talk types (i.e., \(p(\textit{Talk\_Type}(u_{t+1}^{C})\mid\textit{Behaviour}(u_{t}^{T}))\)). While neutral talk is clearly the majority talk type of the client response, in most cases, \(p(\textit{Talk\_Type}(u_{t+1}^{C})=\text{Change}\mid\textit{Behaviour}(u_{t}^{T}))\) is substantially larger in high-quality MI than in low-quality MI regardless of \(\textit{Behaviour}(u_{t}^{T})\), which shows that an MI-adherent counsellor is more likely to evoke Change Talk from the client, irrespective of specific therapist behaviours. On a more granular level, Question is the most likely (31%) therapist behaviour in high-quality MI to evoke Change Talk, which may be because some  
\begin{table}
\begin{tabular}{c c c} \hline \hline  & **High-Quality MI** & **Low-Quality MI** \\ \hline _Reference_ & 28\% & 7\% \\ _Question_ & 28\% & 32\% \\ _Input_ & 11\% & 33\% \\ _Other_ & 33\% & 28\% \\ \hline \hline \end{tabular}
\end{table}
Table 11: (Main) Behaviour distributions in high- and low-quality MI.  
the therapist questions lead to Change Talk more often, such as asking the client what steps they could take towards a behaviour change or how confident they are about adopting a change. Interestingly, Input results in more Change Talk (21%) than any other therapist behaviour in low-quality MI, but it is also the therapist behaviour that prompts the most (23%) sustain talk, which may suggest that the effect of frequent input--characteristic of low-quality MI, as shown in Table 11--is far from certain in terms of evoking Change Talk and reducing sustain talk.  
Figure 4 shows the posterior distribution of therapist behaviours (i.e., \(p(Behaviour(u_{t+1}^{T})\mid Talk\_Type(u_{t}^{C}))\)). One can observe that MI-adherent therapists in general use considerably more reflections than non-adherent therapists do--30% vs. 12%--in response to Change Talk, which suggests that high-quality MI utilises Reflection to reinforce willingness to change. On the other hand, the most commonly shown therapist behaviour in response to Sustain Talk in high-quality MI is Reflection (37%), while the dominant pattern of reacting to Sustain Talk in low-quality MI is Input (54%). This contrast serves as strong evidence that MI-adherent therapy focuses more on showing empathy and trying to understand the client when faced with resistance, including through Reflection, whereas a non-adherent therapist is more likely to try to challenge, correct, or persuade the client through more Input--a common mistake in MI non-adherent therapy [1].