A company designing a new website for its customers is deciding between 3 different user interfaces (UI). The company wants to select the UI that will make their users the happiest. The research department creates a multigroup design test, which includes asking the study participants (that have been randomly assigned to groups) to perform the same specific task on the website. The researchers would like to capture the happiness level and contentment of the users after completing the task. What would be considered the dependent variable