Test screenings involve showing a movie to a sample audience before its release to assess reactions and make improvements. Critic screenings are invitation-only viewings for national critics to meet press deadlines. Focus groups involve formal screenings with 25-30 people who fill out surveys and participate in discussions about the film. Private screenings are for investors and VIPs, while preview screenings may be used to finalize marketing strategies based on audience feedback collected at public boutique theaters. Sneak previews are unannounced public screenings held before the official release date.