Energies 2015,8 11008 Within the boundary of peer-pressure concept,Word-of-Mouth (WOM)a type of informal, occupant-to-occupant,face-to-face communication [133]is considered a very influential communication method to influence occupancy-related behaviors [110].WOM includes relating pleasant information and recommendations to others [134].In energy-related research,WOM is typically employed when occupants with various energy characteristics share a common space [28],and it can be significantly effective in improving occupant energy-use behaviors [135].Azar and Menassa [28,80]studied WOM interactions among 10 students in a small graduate student office building in a 40-month period to understand how occupants from different groups with different energy use behaviors can influence others within their group and in other groups.In their research,they considered three groups of occupants: high-energy consumption,medium energy consumption,and low energy consumption.The results indicate the effectiveness of WOM to adopt energy saving behaviors among high and medium energy consumption categories and convert them to low energy consumption category.However,WOM is obviously connected to occupants'social structures/networks,and such WOM interactions need to be evaluated through medium or big office buildings since the structures/networks of small offices are completely different with other sizes of office buildings. 4.2.Feedback Techniques Feedback techniques typically provide occupants with their energy-use information.A growing body of energy-saving literature has shown that feedback is a more prevalent and cost-effective intervention technique than occupancy interaction for bringing about reductions in energy use.The earliest studies in this field date back to the 1970s.For example,in 1977,Seligman and Darley [136]provided daily electrical energy use feedback to a group of households within a one-month period;they saw an 11 percent reduction in energy use.In 1980,a United States local T.V.channel in West Texas provided information about the amount of gasoline people used daily via a nightly news television program [137]. The results showed a reduction of up to 31.5 percent in fuel consumption. Feedback techniques are generally divided into continuous and discrete techniques (see Figure 3). In continuous techniques,the energy-use related information is typically provided to occupants through bulletins and announcements installed on boards located in places where occupants have the opportunity to see the information every time they are nearby.However,discrete techniques provide information periodically.For example,occupants could be informed about their energy-use information via weekly e-mail. There are certain characteristics that help a feedback technique to be more effective.The most important characteristic emphasizes giving positive comments to occupants rather than negative ones (e.g.,using language such as"saved"instead of"wasted").Comments on specifics energy behaviors are also more effective than general comments.Overloading on feedback tends to reduce occupant's ability to effectively use comments [138];therefore,a well-timed plan regarding when to provide feedback to occupants is also important. In particular,representative units significantly affect the success of feedback.There are three meaningful units for representing the energy-saving related feedback [139]:(1)Direct energy units (e.g.,kWh);(2)Monetary units(e.g.,$)and(3)Environmental externality units (e.g.,greenhouse gas emission).The representative unit has a significant influence on occupants'behaviors as it effectivelyEnergies 2015, 8 11008 Within the boundary of peer-pressure concept, Word-of-Mouth (WOM)—a type of informal, occupant-to-occupant, face-to-face communication [133]—is considered a very influential communication method to influence occupancy-related behaviors [110]. WOM includes relating pleasant information and recommendations to others [134]. In energy-related research, WOM is typically employed when occupants with various energy characteristics share a common space [28], and it can be significantly effective in improving occupant energy-use behaviors [135]. Azar and Menassa [28,80] studied WOM interactions among 10 students in a small graduate student office building in a 40-month period to understand how occupants from different groups with different energy use behaviors can influence others within their group and in other groups. In their research, they considered three groups of occupants: high-energy consumption, medium energy consumption, and low energy consumption. The results indicate the effectiveness of WOM to adopt energy saving behaviors among high and medium energy consumption categories and convert them to low energy consumption category. However, WOM is obviously connected to occupants’ social structures/networks, and such WOM interactions need to be evaluated through medium or big office buildings since the structures/networks of small offices are completely different with other sizes of office buildings. 4.2. Feedback Techniques Feedback techniques typically provide occupants with their energy-use information. A growing body of energy-saving literature has shown that feedback is a more prevalent and cost-effective intervention technique than occupancy interaction for bringing about reductions in energy use. The earliest studies in this field date back to the 1970s. For example, in 1977, Seligman and Darley [136] provided daily electrical energy use feedback to a group of households within a one-month period; they saw an 11 percent reduction in energy use. In 1980, a United States local T.V. channel in West Texas provided information about the amount of gasoline people used daily via a nightly news television program [137]. The results showed a reduction of up to 31.5 percent in fuel consumption. Feedback techniques are generally divided into continuous and discrete techniques (see Figure 3). In continuous techniques, the energy-use related information is typically provided to occupants through bulletins and announcements installed on boards located in places where occupants have the opportunity to see the information every time they are nearby. However, discrete techniques provide information periodically. For example, occupants could be informed about their energy-use information via weekly e-mail. There are certain characteristics that help a feedback technique to be more effective. The most important characteristic emphasizes giving positive comments to occupants rather than negative ones (e.g., using language such as “saved” instead of “wasted”). Comments on specifics energy behaviors are also more effective than general comments. Overloading on feedback tends to reduce occupant’s ability to effectively use comments [138]; therefore, a well-timed plan regarding when to provide feedback to occupants is also important. In particular, representative units significantly affect the success of feedback. There are three meaningful units for representing the energy-saving related feedback [139]: (1) Direct energy units (e.g., kWh); (2) Monetary units (e.g., $); and (3) Environmental externality units (e.g., greenhouse gas emission). The representative unit has a significant influence on occupants’ behaviors as it effectively