If you were a psychologist and you wanted to study whether reading to children would affect their reading ability once they entered school, which of these methods would be most useful and which would...

If you were a psychologist and you wanted to study whether reading to children would affect their reading ability once they entered school, which of these methods would be most useful and which would be least useful?  Answer this question by ranking them 1 (most useful) to 9 (least useful)

_____ Laboratory Study

_____ Field Study

_____ Survey Method

_____ Naturalistic Observation

_____ Interview

_____ Case Study Method

_____ Psychological Test

_____ Longitudinal Method

_____ Cross-Sectional Method