H.B.Gunay et al.Building and Environment 70(2013)31-47 39 (a) (b) 0.8 G Onen △ -△Sometimes/Seldom 5 0.6 Q 号 0.6 0.4 △ A 0.4 0.2 只 22 24 26 子 0 200 400 600 800 Temperature (C) Workplane illuminance (lux) (c) 0,8 0.6 0.4 0.2 2000 4000 6000 8000 Workplane illuminance (lux) Fig.4.(a)Window opening behavior of participants that defined themselves as passive,medium,and active occupants in a survey 40].(b)manual light use behavior in ten single or double occupied offices [56].(c)manual blinds use behavior in ten single or double occupied offices [64]. given that the occupants would finish that cold drink at once in a level adjustments based on the outdoor temperature was a pre- short period of time.However,drinking as a behavioral adaptation dictive measure.For example,on a warm day that is followed by a to the environment can be further investigated by monitoring the cold day,occupants would likely wear heavier clothes based on beverage size and temperature. their experience.This type of behavior was distinguished with the Time discretization of the self-reported questionnaire ranged diurnal clothing level variations such as taking off a jacket or a from one per hour [112]to two per day [108.111.113].This is also sweater.Therefore,people's long-term clothing selections are restrained by the practical reasons associated with participants.For based on the short term history of the outdoor conditions and the example,sometimes volunteers were given the option to select the short-term clothing level adjustments are based on the current frequency (i.e.either 2 or 3 times a day)of the pop-up question- indoor temperature [108.In a more recent study,Schiavon and Lee naire on their computer [108].This questionnaire in Haldi and [107]elaborated this by suggesting two models.Of these,one used Robinson[108]asked occupants whether or not they changed their the outdoor temperature (at 6 am)as a predictor variable and the clothing ensemble,activity type and drank a cold/hot drink in the other included both the outdoor temperature and the operative previous hour.Another problem associated with this type of temperature as predictor variables.However,these models could questionnaire surveys is the bias of the self-reported data.Veitch only predict a small portion of the clothing level variances and it et al.[66]reported that people perceived themselves more active was concluded that indoor and outdoor climate can only account than they actually were.Moreover,so-called "Hawthorne effect" for a small portion of human clothing behavior.This may be an suggests that occupants behave differently when they know that indication of non-adaptive,perhaps habitual and task based nature they are monitored [114].Therefore,attention must be paid while of human clothing behaviors which underlines the inherent diffi- interpreting the self-reported activities and these should be sup- culty in predicting them.Similarly,beverage temperature selec- ported with other observations carried out by the researchers. tions (e.g.cold/hot drink)were observed to follow the long-term outdoor temperature variations [108.The adjustment of the ac- 2.2.3.Physical variables tivity rate was observed with respect to the indoor and the outdoor Indoor[100,102,108,1121 and outdoor[100,102.110.1151tem- temperature [108,113].However,given that in offices,activity was peratures were monitored as variables to be utilized in the restrained with the task (e.g.sedentary).no strong relationship modeling stage.Haldi and Robinson [108]reported that clothing could be proposed based on these observations [108.113].given that the occupants would finish that cold drink at once in a short period of time. However, drinking as a behavioral adaptation to the environment can be further investigated by monitoring the beverage size and temperature. Time discretization of the self-reported questionnaire ranged from one per hour [112] to two per day [108,111,113]. This is also restrained by the practical reasons associated with participants. For example, sometimes volunteers were given the option to select the frequency (i.e. either 2 or 3 times a day) of the pop-up question￾naire on their computer [108]. This questionnaire in Haldi and Robinson [108] asked occupants whether or not they changed their clothing ensemble, activity type and drank a cold/hot drink in the previous hour. Another problem associated with this type of questionnaire surveys is the bias of the self-reported data. Veitch et al. [66] reported that people perceived themselves more active than they actually were. Moreover, so-called “Hawthorne effect” suggests that occupants behave differently when they know that they are monitored [114]. Therefore, attention must be paid while interpreting the self-reported activities and these should be sup￾ported with other observations carried out by the researchers. 2.2.3. Physical variables Indoor [100,102,108,112] and outdoor [100,102,110,115] tem￾peratures were monitored as variables to be utilized in the modeling stage. Haldi and Robinson [108] reported that clothing level adjustments based on the outdoor temperature was a pre￾dictive measure. For example, on a warm day that is followed by a cold day, occupants would likely wear heavier clothes based on their experience. This type of behavior was distinguished with the diurnal clothing level variations such as taking off a jacket or a sweater. Therefore, people’s long-term clothing selections are based on the short term history of the outdoor conditions and the short-term clothing level adjustments are based on the current indoor temperature [108]. In a more recent study, Schiavon and Lee [107] elaborated this by suggesting two models. Of these, one used the outdoor temperature (at 6 am) as a predictor variable and the other included both the outdoor temperature and the operative temperature as predictor variables. However, these models could only predict a small portion of the clothing level variances and it was concluded that indoor and outdoor climate can only account for a small portion of human clothing behavior. This may be an indication of non-adaptive, perhaps habitual and task based nature of human clothing behaviors which underlines the inherent diffi- culty in predicting them. Similarly, beverage temperature selec￾tions (e.g. cold/hot drink) were observed to follow the long-term outdoor temperature variations [108]. The adjustment of the ac￾tivity rate was observed with respect to the indoor and the outdoor temperature [108,113]. However, given that in offices, activity was restrained with the task (e.g. sedentary), no strong relationship could be proposed based on these observations [108,113]. Fig. 4. (a) Window opening behavior of participants that defined themselves as passive, medium, and active occupants in a survey [40], (b) manual light use behavior in ten single or double occupied offices [56], (c) manual blinds use behavior in ten single or double occupied offices [64]. H.B. Gunay et al. / Building and Environment 70 (2013) 31e47 39