Answer to Question 1
Focus groups are moderator-led small group (812 people) interviews. The topics are available to the moderator on a rough outline instead of a specific survey format. Group members are relatively homogeneous, and interaction is expected. Participants are exposed to the ideas of the other group members and can respond to those ideas with ones of their own. Nominal groups are similar in all these areas. The key difference is that nominal group moderators ask participants to provide written responses prior to opening group discussion. It is believed this subtle difference does a lot to help avoid group think.
Answer to Question 2
A