Final answer:
Proprietary interfaces can be wasteful of time and resources during development and cause difficulty for users due to their lack of standardization and interoperability. Standards-based interfaces like HL7 are generally more efficient and user-friendly.
Step-by-step explanation:
The communication systems that can be wasteful of time and resources during development and add difficulty for users are proprietary interfaces. Proprietary interfaces are those that are owned by a company and not based on a standard; they can require significant investment to develop and maintain. This development often results in a lack of interoperability with other systems, which in turn can lead to inefficiencies and increased costs. Users may also find it difficult to work with these systems if they are accustomed to using standard interfaces.
On the other hand, standards-based interfaces, such as HL7 in healthcare, promote interoperability and can be more efficient in the long term. They are designed to work across various systems and thus, save time and resources. User interfaces are focused on the design and interaction between users and computers, and aren't necessarily wasteful unless poorly designed. It is the responsibility of developers to ensure that effective communication is maintained while focusing on user-friendliness and adherence to standards.