## 1 Introduction
### The Case Study under Application: The CEMEC Project in a Nutshell  
Experimentation with holographic showcases was carried on in the framework of the European Connecting Early Medieval European Collections (CEMEC) project in 2015-2019 ([[https://www.cemec-eu.net/](https://www.cemec-eu.net/)]([https://www.cemec-eu.net/](https://www.cemec-eu.net/)), accessed on 5 November 2021), where universities and research institutions, museums, and technical partners cooperated to advance the knowledge and promotion of the Early Medieval arts and cultures of different European regions, particularly in the museology sector. A traveling exhibition was created (2017-2019) which visited different European countries and where the holographic showcase was presented and evaluated in relation to its impact on the public and to different museum objects. Efforts have been oriented toward the creation of a so-called \"box of stories\" and the definition of a coherent communicative format, where the (1) real and digital contents, (2) structure, (3) materials, (4) interior set-up, (5) illumination, (6) perception, (7) audio-visual grammar, (8) narrative approach and dramatization, and (9) scalability are designed as a coherent \"communication eco-system\" [1].  
The \"box of stories\" has been used to tell the story of some objects of the seventh century A.D., which was taken into account for the CEMEC project ([[https://vimeo.com/285977554](https://vimeo.com/285977554)]([https://vimeo.com/285977554](https://vimeo.com/285977554)); [[https://vimeo.com/236305120](https://vimeo.com/236305120)]([https://vimeo.com/236305120](https://vimeo.com/236305120)), accessed on 5 November 2021), and they were the following:  
* The Kunagota sword: an Avar sword exhibited at the National Hungarian Museum of Budapest.
* The Mytilene treasure: a set of 70 Byzantine objects from the Byzantine and Christian Museum of Athens. Three representative objects of the treasure--a golden bracelet, a candlestick, and a trulla (a tool for water spilling)--were chosen for the holographic showcase.  
The Brooch from Bonn: a golden disk-shaped brooch exhibited at the LVR LandesMuseum of Bonn.
* The Brooch from Kolked: a golden brooch exhibited at the National Hungarian Museum of Budapest.
* The Buckle of Kolked: a golden buckle exhibited at the National Hungarian Museum of Budapest.
* The holographic showcase saw **different set-ups** according to the available spaces in each venue of the \"Crosswords\" exhibition (e.g., big holographic showcase, small holographic showcase, showcase surrounded by a projection wall, or video on a TV screen):
* Budapest: Hungarian National Museum (HNM);
* Amsterdam: Allard Pierson Museum (APM);
* Athens: Byzantine and Christiane Museum (BCM);
* Bonn: LVR LandesMuseum (LVR).  
We created a precise storytelling according to the selected museum objects (although starting from a common approach) and we tried to solve engineering issues, which we developed and adapted them to from time to time. In addition, the position of the holographic showcase was decided each time upon several evaluations made by local curators, architects, technicians, and directors.  
The results of the UX evaluations made in each venue helped the CNR ISPC team to improve the overall structure as well as the storytelling duration and usability.  
For the purpose of this manuscript, the discussion is focused on the evaluation conducted on only two objects: the **Kunagota sword and some selected artifacts of the Myti-**lene Treasure** (Figure 1). Not all venues hosted the same configurations of these objects, but the evaluation involved the same set of questions and evaluative issues and requirements.