Researchers at the University of Utah carried out a study to see if the size of the fork used to eat dinner has an effect on how much food is consumed (Food Network Magazine, January 2012). The researchers assigned people to one of two groups. One group ate dinner using a small fork, and the other group ate using a large fork. The researchers found that those who ate with a large fork ate less of the food on the plate than those who ate with the small fork. The title of the article describing this study was “Dieters Should Use a Big Fork.” This title implies a cause- and-effect relationship between fork size and amount eaten and also generalizes this finding to the population of dieters. What would you need to know about the study design to determine if the conclusions implied by the headline are reasonable? Use the following information to answer Exercises 1.56 – 1.60. The paper “Turning to Learn: Screen Orientation and Reasoning from Small Devices” ( Computers in Human Behavior [ 2011]: 793– 797) describes a study that investigated whether cell phones with small screens are useful for gath-ering 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 psychol-ogy course at a large public university to one of two groups at random. One group read material that was displayed on 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).
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.