The adoption of IoT devices has expanded due to their benefits, and the Web of Things (WoT) standard has further simplified access. However, enabling end users - especially non-technical ones - to compose WoT environments remains complex due to challenges in expertise, effort, and time. This thesis systematically analyzes the situation, identifying three key barriers: insufficient interoperability, usability, and usefulness. A set of requirements for end-user Things composition is derived and used to assess existing WoT research, revealing shortcomings in supporting heterogeneous Things...