Laura used to go to a restaurant near her home. During her past few visits to the restaurant, the staff were rude and the food was served cold, even though she would always include a generous tip with the bill. This scenario exemplifies , according to which Laura did not perceive fairness in the exchange.

"six months ago, several of molly's friends joined the trimtime fitness center. each of them participated in trimtime's weight-reduction and fitness regimen. all reported substantial weight reduction, and all are visibly slimmer. molly is convinced. she joins trimtime and enrolls in the program, hoping and expecting to see the same results. she is especially delighted to learn that trimtime had adjusted its program to make it even more effective in a shorter period of time." what is the feature in question/attribute of interest in this argument?