Energies 2015,8 11010 studies is relatively hard work.Collecting data after each feedback to fully understand how the feedback influences occupant behavior over time would also be necessary,but Matthies et al.[45]and Carrico and Reimer [132]only looked at overall energy reduction.One likely reason for the limited examination is that separately analyzing the data from each feedback would be a highly time-consuming activity for their studies. Research also shows that comparative feedback among different groups is more effective than individual feedback for changing behavior strategies [146].Occupants in commercial buildings typically work in different groups,and information about the outcomes of other groups mostly leads to competitive feelings and the motivation for better performance.Therefore,comparative,group-based feedback yields more energy-saving actions than groups who only received feedback about their own actions [146]. In fact,providing individual occupants with access to the energy information of others in their organization can result in significant energy savings [68].Siero et al.[147]studied the effect of environmental feedback on occupants of two units of a company over a four-month period.They chose two units with the same social structures and personal characteristics.The weekly feedback was presented through various energy bulletins and announcements.Occupants of the first group just received the feedback for their own behavior;however,the second unit received information both regarding their own energy-use behavior as well as comparative feedback about the first group.The results show the second unit saved more energy than the first unit.In addition,occupants in the second group reported being more competitive at the end of the study than the first group,and they also continued their energy-savings behaviors after completing the study.Similar to the Siero et al.[147],Gulbinas and Taylor [68]and Peschiera and Taylor [123]divided their occupant samples into two groups and provided a comparative feedback for one group.Their results also indicate the comparative method is more effective than individual feedback.They also discussed how occupants who receive energy-use feedback only for their own behavior may not have sufficient information to significantly improve their energy-use behaviors. However,although all of these comparative feedback research projects indicated that comparative feedback would encourage occupants to save energy;they do not provide any insight about the negative impact of comparative feedback.In such a case,occupants in a comparative feedback group could be negatively impacted by the information that shows that they consume more energy than other groups. Understanding the individual energy-efficiency behavior of each occupant can lead to providing better energy-saving feedback to individual occupants.The energy consumption of appliances of individual occupants (e.g.,personal computer,desk lamp)is typically less than 10 percent of overall energy use in commercial buildings [148,149],and a workdesk can offer the simplest environment in such buildings for understanding individual occupant's energy behaviors [45].Murtagh et al.[46] investigated the influence of individual feedback on energy use in commercial buildings.They chose a case study of 83 office workers at a medium-sized university in the south of England and measured their energy consumption at the desk level within an 18-week period-each desk was under control of an individual occupant.Then,Murtagh et al.[46]provided an environmental externalities-based feedback named MyEcoFootprint to all individual occupants.Their results indicate a significant energy reduction. Similarly,Staats et al.[145]provided individual feedback to occupants once within the last two weeks of the second intervention period (i.e.,the second winter).They gave each occupant a separate personal letter that provided information about the particular windows and thermostats within his/her office space. This information,for example,could have revealed to an occupant that the window of his/her space wasEnergies 2015, 8 11010 studies is relatively hard work. Collecting data after each feedback to fully understand how the feedback influences occupant behavior over time would also be necessary, but Matthies et al.[45] and Carrico and Reimer [132] only looked at overall energy reduction. One likely reason for the limited examination is that separately analyzing the data from each feedback would be a highly time-consuming activity for their studies. Research also shows that comparative feedback among different groups is more effective than individual feedback for changing behavior strategies [146]. Occupants in commercial buildings typically work in different groups, and information about the outcomes of other groups mostly leads to competitive feelings and the motivation for better performance. Therefore, comparative, group-based feedback yields more energy-saving actions than groups who only received feedback about their own actions [146]. In fact, providing individual occupants with access to the energy information of others in their organization can result in significant energy savings [68]. Siero et al. [147] studied the effect of environmental feedback on occupants of two units of a company over a four-month period. They chose two units with the same social structures and personal characteristics. The weekly feedback was presented through various energy bulletins and announcements. Occupants of the first group just received the feedback for their own behavior; however, the second unit received information both regarding their own energy-use behavior as well as comparative feedback about the first group. The results show the second unit saved more energy than the first unit. In addition, occupants in the second group reported being more competitive at the end of the study than the first group, and they also continued their energy-savings behaviors after completing the study. Similar to the Siero et al. [147], Gulbinas and Taylor [68] and Peschiera and Taylor [123] divided their occupant samples into two groups and provided a comparative feedback for one group. Their results also indicate the comparative method is more effective than individual feedback. They also discussed how occupants who receive energy-use feedback only for their own behavior may not have sufficient information to significantly improve their energy-use behaviors. However, although all of these comparative feedback research projects indicated that comparative feedback would encourage occupants to save energy; they do not provide any insight about the negative impact of comparative feedback. In such a case, occupants in a comparative feedback group could be negatively impacted by the information that shows that they consume more energy than other groups. Understanding the individual energy-efficiency behavior of each occupant can lead to providing better energy-saving feedback to individual occupants. The energy consumption of appliances of individual occupants (e.g., personal computer, desk lamp) is typically less than 10 percent of overall energy use in commercial buildings [148,149], and a workdesk can offer the simplest environment in such buildings for understanding individual occupant’s energy behaviors [45]. Murtagh et al. [46] investigated the influence of individual feedback on energy use in commercial buildings. They chose a case study of 83 office workers at a medium-sized university in the south of England and measured their energy consumption at the desk level within an 18-week period—each desk was under control of an individual occupant. Then, Murtagh et al. [46] provided an environmental externalities-based feedback named MyEcoFootprint to all individual occupants. Their results indicate a significant energy reduction. Similarly, Staats et al. [145] provided individual feedback to occupants once within the last two weeks of the second intervention period (i.e., the second winter). They gave each occupant a separate personal letter that provided information about the particular windows and thermostats within his/her office space. This information, for example, could have revealed to an occupant that the window of his/her space was