The following questions are all weighted equally (2 points each). Please be brief.

1. Explain some limitations of written surveys for evaluating user interfaces.
    
2. What is Shneiderman's position on the use of agents in HCI? Explain at least two key issues.
    
3. Say what is "tacit knowledge" and give an example.
    
4. Say what is a "mitigated speech act," give an example, and explain why this concept is relevant to HCI.
    
5. Define Peirce's notion of symbol, and give an example that is relevant to HCI.