“Some people hate them and are very frightened of them but I love them,” Walker said. “There’s nothing like sitting in an audience with other people and feeling how the film is going down. You can tell, absolutely, when a film is working and cooking and you can tell when it isn’t and when people are restless.”

Walker added, “The edit is about managing that sync between if you are ahead of the audience or if you are behind. You never want to be behind. Test screenings reveal that. You have to be in a position of trust with your producers, if you are not then [test screenings are] a weapon otherwise.” The test screening process proved crucial during the editing of Villeneuve’s “Arrival.” As the editor explained, “You wanted to get people at the end of the film understanding the [time twist] enough to have them be able to have the feelings we wanted them to have at the end. If you weren’t sure, then you wouldn’t have those feelings. We had very worrying test screenings where people just didn’t get the basic tenet of the film. People being very smart, they invent their own reasons for what’s in front of them and they weren’t what we wanted them to be. So we kept going back to the drawing board of making it clearer in some way.” The “Arrival” test screenings guided Walker and Villeneuve in their reshaping of the film and pushed them to have the most clear theatrical cut possible. Roger Deakins’ wife and key collaborator James Deakins said she understood where Walker was coming from, but she did call attention to the manipulative nature of test screenings. “They’re bringing in an audience,” James Deakins said. “The one thing I think about test screenings is you bring these people in and you give them the treat about seeing this movie, and then you give them questions and they feel like they should answer. If the question is, ‘What did you not like about the main character?’ They’re going to have to find something because they were just giving this treat and they feel like they owe it. I think that’s a problem. Sometimes you get things that wouldn’t have come up if you didn’t set it up that way.” Roger Deakins said he is more in James’ camp than in Walker’s when it comes to test screenings. saying, “I agree [with James]. You sit there and feel the audience reaction and that tells you more than any kind of form or question [the test audience] would have to fill in. Because in that case they can create something that’s not really their reaction to it. They need numbers.”

Walker is currently editing Villeneuve’s “Dune,” which Warner Bros. has set on the release calendar for December 18. Sign Up: Stay on top of the latest breaking film and TV news! Sign up for our Email Newsletters here.