# Service-Aware Interactive Presentation of Items for Decision-Making
## Materials and Methods
### Specification of the Dimensions of Item Evaluation  
In order to define the evaluation dimensions to be used for presenting items we apply the Service Journey Maps (SJM) [24], which describe the typical flow of user activities that a participant, service provider, or other stakeholder perform in a service execution; see the upper boxed portion of Figure 1. In the map, each activity is encapsulated in a touch-point (stage) represented as a gray circle. An actor can either initiate a touch-point or be involved in it through some inputs or outputs. The former case is represented by a plain open arrow, such as the one connecting customer/user to Stage 1; the latter one is represented by means of dashed lines. The arrows connecting touch points specify their order within the overall workflow. The level of touch point details depends on the nature of the services being modeled as well as on the association between the service stages and the user experience.  
The set \(\mathcal{D}\) of evaluation dimensions describing user experience with items includes high-level concepts \(\{d_{1},\ldots,d_{v}\}\) that are retrieved from the stages of service fruition. In general, we might have a one-to-one correspondence between evaluation dimensions and stages. However, for finer-grained reasoning, we might want to identify multiple dimensions relevant to a single stage; moreover, a single dimension could be related to different stages. In order to comply with these requirements, we keep stages and evaluation dimensions as separate concepts and we model the associations between them as [M, N] relations; see the lower portion of Figure 1.  
Notice that reviews rarely mention evaluation dimensions explicitly: most comments refer to item features that have to be mapped to a dimension to support their identification. For instance, the host appreciation in the home booking domain might be described by making reference to her/his family and hospitality or to other aspects of the interaction such as her/his helpfulness. In order to identify the sentences that deal with these dimensions, a thesaurus \(\mathcal{T}_{i}\) of keywords has to be built for each evaluation dimension \(d_{i}\). The thesauri can be defined using previous studies of the service domain. Notice that the keywords of the thesauri must be lemmatized to have a single, base format for each of them; for this purpose, we use the spacy Python library [87].  
As described in Section 4.2 for home booking, the identification of evaluation dimensions \(\{d_{1},\ldots,d_{v}\}\) starting from the stages of a Service Journey Map is a possibly iterative process and it is strictly intertwined with thesaurus construction:  
1. We start with a one-to-one association between stages and evaluation dimensions.
2. We build a first version of a thesaurus \(\mathcal{T}_{i}\) for each identified dimension \(d_{i}\).
3. We analyze each of the defined thesauri and we detect: * Dimensions that need a finer-grained representation because the associated keywords refer to topics describing service aspects that deserve to be promoted to dimensions. For instance, the \"Stay in apartment\" stage can be associated to distinct dimensions to separately evaluate the internal environment of the home and its surroundings. * Keywords related to aspects that are relevant to more than one stage, such as the interaction with the host: these aspects can be promoted to evaluation dimensions associated with multiple stages.  
It can be noticed that the performance of roles in delivering the service along stages can have an important impact on the construction of thesauri and, consequently, on the definition of the evaluation dimensions to be modeled. For instance, in a Service Journey Map describing the experience of customers in a restaurant, the waiter's behavior and attitudes highly influence the experience in stages such as \"order meal\" and \"consume meal\".