Designing good digital experiences for children can be difficult; designers have to consider children's cognitive and motor skill limitations, understand their target audience, create something entertaining and educational, comply with national and international jurisdiction, and at the same time appeal to parents. We set out to create a general framework which designers and developers can use as a foundation and testing ground for their digital products in the field of user experience. The methods used during the thesis include interviews, literature studies, user testing, case studies, personas, prototyping, and more. The results created are primarily user experience guidelines packaged in a Theoretical Framework, user testing conclusions, along with suggestions on improving the current Lego Star Wars: Force Builders application, a few in the form of prototypes.

Creating immersive experiences for virtual reality (VR) presents new design opportunities and challenges that do not appear when creating experiences on a screen. Creating prototypes and exploring concepts in VR is today limited to professionals with previous knowledge in 3D application development, and testing 3D experiences requires the usage of an Head-Mounted Display (HMD), which forces professionals to switch medium from the computer to an HMD. With new advances in this field, there have to be new solutions to these challenges. The goal of this thesis is to explore how VR technology can be utilized in the experience design process for VR. This is achieved through a literature study and conducting expert interviews, followed by a hardware evaluation of different HMDs and concept creation using rapid prototyping. From the interviews, a number of issues could be identified that correlates with the research from the literature study. Based on these findings, two phases were identified as suitable for further improvements; Concept prototyping and testing/tweaking of a created experience. Lo-fi and hi-fi prototypes of a virtual design tool were developed for HTC Vive and Google Daydream, which were selected based on the hardware evaluation. The prototypes are designed and developed, then tested using a Wizard of Oz approach. The purpose of the prototypes is to solve some of the issues when designing immersive experiences for HMDs in the suitable experience design phases that were identified by analyzing the interview results. An interactive testing suite for HTC Vive was developed for testing and evaluation of the final prototype, to verify the validity of the concept. Using Virtual Reality as a medium for designing virtual experiences is a promising way of solving current issues within this technological field that are identified in this thesis. Tools for object creation and manipulation will aid professionals when exploring new concepts as well as editing and testing existing immersive experiences. Furthermore, using a Wizard of Oz approach to test VR prototypes significantly improves the prototype quality without compromising the user experience in this medium.