1. What are the differences between "Content Validity" and "Criterion Validity"?

2. TOEFL test is a kind of "communicative test". Because its testing sections fit the three of four characteritics of communicative test: 1. information gap 2. intergration of test tasks and content within a given domain of discourse 3. attempts to measure a much broader range of language abilities.

3. The oral test of IELTS is a "live" performance and involves a one-on-one tester/test-taker relationship, but TOEFL test doesn't ( it records the oral production by computer)