The paper Turning to Learn Screen Orientation and Reasoning from Small Devices describes a study that investigated whether cell phones with small screens are useful for gathering information The researchers wondered if the ability to reason using information read on a small screen was affected by the screen orientation The researchers assigned 33 undergraduate students who were enrolled in a psychology course at a large public university to one of two groups at random One group read material that was displayed a small screen in portrait orientation and the other group read material on the same size screen but turned to display the information in landscape orientation see the following figure Portrait Landscape The researchers found that performance on a reasoning test based on the displayed material was better for the group that read material in the landscape orientation Is the study described above an observational study or an experiment Oan observational study an experiment