Interoperability is the ability of two or more systems to exchange information and use the exchanged information without special effort on the part of either systems (ALA, 2000; Zeng and Chan, 2004). It is also the quality of a system, which interface(s) is understood clearly enough to work with other systems, whether now or in future, either for implementation or access, without restrictions (McCrees and Daniel, 2017). This paper draws from this delineation to present interoperability as a noesis, which abstraction is conceptualizable as an interface. There are different types of interfaces, but we consider the User Interface (UI). Interestingly, interoperability cannot be ignored since Knowledge Organization Systems’ (KOSs) source(s) and target system(s) have their own structures and characteristics. KOSs as an information resource supports the description and retrieval of information from heterogeneous sources. Its vastness presents the challenge of how users can be helped with access to information and then achieve the “best retrieval results”. In the context of user-centricity; “best retrieval results” will be the results that satisfy the Information need(s) (IN) of users. This poses the question of the use of having access to information if the information will not meet the IN of users. In KOS literature effort has been made to introduce interoperability within a single search apparatus (Zeng and Chan, 2004). However, there is the need to also render different KOS interoperable within aggregate search platforms since there are KOS for different purposes. Currently, the digital environment has become a bargain for more possibilities of information presentation and access. The challenge with this is as (much) intellectual as it is technical if KOSs that are useful for end-users are to be developed.

Going by the postulation of Zeng et al. (2007), interoperability in this paper is the possibility for different KOS to communicate with each other with no dependence on a precise actor based on the existence of an open standard - a UI. Moreover, KOS is layered: its theoretics; its structures and symbols; and the digital aspect(s). Its application(s) is the last layer that uses the other layers to offer information access and services to satisfy users’ needs (Gnoli, 2013). This paper seeks to draw a connection between User Experience (UE) and Interactivity and the possibilities they can make happen if they exist on KOS UIs. The continuous disparate source(s) and heterogenous target system search engines - the example KOS in this paper - draw from to meet users’ needs highlight the need to find this link. This necessity is plausible knowing that KOSs (we believe) can still provide information access even as services towards “best retrieval results” despite the current level of its interoperability. This paper, therefore becomes necessary, considering the provisions, UE, Interactivity and other user-related attributes can bring to bear if properly understood. For example, a good UI should collate users’ IN(s) as if it completely understands them for better UE and Interactivity to be guaranteed. As a result, a UI can assist even users to realize definite goals (of information access) with satisfaction in a specified context of use. The outcome of this paper will be useful in the attempt to remove the difficulty that exists based on the wide range of people with different goals that use KOS. Thus, a UI that harnesses the attributes of EU and Interactivity to meet the IN of users irrespective of their goal(s) might will be helpful.

The postulation presented so far is paramount since users use KOS even on the fly with devices that use touch-screens, which presents a whole new twist, thus necessitating the need to establish the connection this paper seeks to present. So as not to violate the general principles of UI design expecially “user control and freedom” we are conscious of the fact that UE attribute in UIs may tilt towards unmanaged control and freedom. With Interactivity’s attribute, such control can be put in the hands of users. We would therefore draw on the constructivist theory to highlight the fact that users can form their own knowledge. And as such users should be able to use the control and freedom presented by UIs towards achieving “best retrieval results”. UE and Interactivity attributes will be majorly conceptualized in a qualitative and quantitative research methodological framework to use ordinal data. A measurement model as instrument and scale will be proposed empirically using the exploratory factor analysis procedure, which result will be translated into personas for further validation following the provisions in literature (Idoughi et al., 2012).

Knowing that interoperability problem in KOS is also a software engineering problem; this paper would contribute to knowledge by presenting useful measurable attributes for the design of UI for KOS. It will also provide the measurement instrument and scale as a model of measurable attributes and information on how to use them. We would therefore conclude that KOS’s success at providing information access and service delivery does not depend solely on the technical aspect of re-engineering KOS’s source and target system for better interoperability. The intellectual aspect, which could encompass UI modelling, based on users’ requirements and contexts would also be important.