1. Introduction
It is widely accepted that enhancing energy efficiency is crucial for reducing greenhouse emissions. To persuade individuals and businesses to use less energy, public policy has been taking greater interest in using energy conservation programs that do not rely on changing energy prices, such as subsidies for those who switch to more energy-efficient appliances. Drawing on insights from cognitive sciences, such energy conservation programs typically carry certain information that nudges energy consumers to reduce their energy use.
One of the most successful of such energy programs is the neighbor comparison information that was run by the US company OPOWER. The US neighbor comparison information program began under the title of home energy reports (HERs) in August 2011. The comparison information played the role of a social norm, inducing people to practice energy and environmental conservation and contributed to a reduction in energy consumption by two percent on average. The effect is equivalent to that of a short-run electricity price increase of 11–20 percent, which translates to annual savings of USD 300 million [
1,
2]. Besides that, there exist sufficient results for how communicating a descriptive norm—how most people behave in a given situation—via information can induce conformity to the communicated behavior on energy resources as well as social beliefs [
3,
4,
5,
6,
7].
By benchmarking the HERs program, the Korean government began the program of neighbor comparison information in 2012. The Korea Energy Agency (KEA), a governmental agency that carried out national energy policies for energy efficiency, officially began supervising the program in 2012 in order to expand it nationwide. KEA reported that 1 million households received neighbor comparison information in their utility statements in 2013 and announced an ambitious plan that the information would be provided to up to 5 million households by 2017.
However, a way of presenting the neighbor comparison information, such as its design, format, and size, is not officially standardized by the KEA but decided by each local community under its own preferences and budget conditions. Some local communities have been presenting the information in the form of bar graph in the middle section of the statement, and some others use customer-friendly designs such as speedometers, animal graphics, and locating it at the top of the statement to be easily visible (see
Appendix A). Taking into account the standard format of the information with content saliency in the HER program, Korean programs lack salience of information, even though salience of information is central to faster and more effective perception of the information.
For a case study, this paper selects a local apartment complex which has been presenting this information in its monthly utility statement as shown in
Figure 1. Not only does the size of the information picture seem to be small, but also the location of the information within the statement is not prominent enough for attracting attention. Because cognitive research suggests that the human eye travels from left to right as well as from top to bottom when they read or scan a simple paper sheet, it is assumed that the information in
Figure 1 is not distinguished, thereby making it hard for the residents to perceive the information in the statement. Furthermore, it is assumed that the residents will become more prone to seeing and perceiving the information if the information is provided with a salient design, namely a larger size and the leftmost location, as shown in
Figure 2.
It is meaningful for academic researchers as well as policy makers to awaken the importance of salience of the neighbor comparison information. For academia, this paper is the first neighbor comparison information study dealing with the importance of salience of the comparison information and its eventual effect on energy conservation. Recent studies on social comparison information expanded their scopes from energy to resources, such as water [
7,
8,
9], but still did not consider the importance of salience of the information. In fact, salience of information is the main topic in the field of cognitive psychology to clarify how salience is related to the perceptions of observers. We found that only a few examples of salience research were conducted from a public policy perspective in recent years, (e.g., [
10]). For policy makers, this paper provides the implication that a public program or policy which was effective in a certain society was not in other societies.
Overall, the aim of this paper is twofold. The first aim of this paper is to check whether residents were more prone to seeing the neighbor comparison information when the statement was provided with salient information design. An eye-tracking experiment is employed for this methodology. The data collected from the experiments on 54 actual residents in the apartment complex will reveal their interests, which are measured by attention time on specific information in the monthly statements as shown in
Figure 1 and
Figure 2. The second aim of this paper is to check whether these subjects considered the neighbor comparison information showing that “My home used 38% more than the average” as a significant determinant of their electricity consumption. Our in-depth interview with these subjects after the eye-tracking experiments will give an answer for the second question. In addition, this paper analyzes the actual utility data on 502 households in the apartment complex to confirm the results from the eye-tracking experiments and the interviews.
The remainder of this paper is organized as follows. The next section reviews existing relevant studies and points out the difference between this paper and the existing literature.
Section 3 provides the eye-tracking experimental results on the moving patterns and duration time of eye-gazing points for two different information designs.
Section 4 presents the post-experiment interview results. Discussion and implications are suggested in
Section 5. Contribution, limitation, and further study are offered in
Section 6.
3. Eye-Tracking Experiment Design
This paper focuses on the case of an apartment complex in Daegu, the third-largest metropolitan city in Korea, where the neighbor comparison information service began being provided to residents’ monthly utility statements in 2015, as shown in
Figure 1. “My neighborhood” was defined in the information as the households living in the same area of units as the resident in the apartment complex. The neighbor comparison information showed how much the resident have consumed more (or less) than their neighborhood in the last month. It is postulated that the information printed in the utility statement was not sufficiently salient for taking significant attention. The actual statement delivered to the residents had too much information to be scrupulously read. Moreover, the resident comparison information was quite small in size and was located in an ambiguous position to draw attention. Therefore, this paper made a controlled version of the utility statement with redesigned resident comparison information that amplified the salience of the information as shown in
Figure 2. For convenience, the actual statement in
Figure 1 is labeled as Statement-1, and the controlled version in
Figure 2 is labeled as Statement-2. The content of the information was identical for the two statements: “My home used 38% more than the average”.
After passing the sufficient time for establishing the program in the community as of the start of the year 2015, it was necessary to check whether the information was operating well in the community, as well as whether more salient information could help gain greater attention from the residents. Two years was set as the sufficient time for establishment in the community. The analysis was designed by the following steps of surveys, eye-tracking experiments, and in-depth interviews, as shown in
Figure 3.
For the first step, we recruited 54 residents of the local apartment community with normal or corrected-to-normal vision by following the method in Rayner’s study [
18]. They were voluntarily applied to the experiment after receiving an official recruiting announcement from the apartment service center and paid to KRW 10,000 (equivalent to approximately USD 10) for each participant. Most of them were females, because the participating condition was to be the “person who is looking mainly at the monthly statement and in charge of paying it”. In addition, they were all naïve with respect to the purpose of the experiment and not requested to provide any privacy information that could be personally identified, such as age, occupation, earnings, or education, except for a couple of residence questions (e.g., how long your residence in this apartment has been and how many residence members you have) in
Table 1.
As the next step, the recruited participants were randomly assigned to either Group A or Group B, with almost equal numbers considered. Both groups were requested to answer survey questionnaires as in [
19], collecting both questionnaire and eye-tracking data. The primary purpose of this survey was to record their general behavior while they were watching the statement, thereby inducing these behaviors to appear naturally during experiment. In addition, this survey helped for cross-checking whether their attention points on the statement collected by the eye-tracking experiment would be consistent with the answers in this survey, because the attention points were recognized as their interests. The survey questionnaire and the answers are summarized in
Table 1. Most of the subjects were interested in payment amounts, such as the total payment, and payment details. Only two subjects of Group A responded with interest in the comparison information. These answers could be evidence that residents in the community consumed energy for their own satisfaction regardless of caring or not caring about social behavior. The survey was meaningful as the preliminary step for a smooth experimental process and for the background information of the subjects, because their private information was not allowed to be collected.
After the simple survey, Group A was requested to see the monitor showing Statement-1, reporting the less-salient information, and Group B was requested to see Statement-2, containing more-salient information. Notices about how-to-dos and what-to-dos were announced. For example, they were requested to use a mouse device, watch the laptop monitor until the end of experiment, and follow the message prompt on the monitor. Additionally, they were strongly recommended to turn off their cellphones to not disturb the ongoing experiment. For the technical equipment and programs for the eye-tracking experiment, this paper used WebGazer.js, created by the Brown HCI Group. WebGazer.js is an eye tracking library that uses common webcams to infer the eye-gaze locations of persons on a webcam in real time. WebGazer contains an automatic face-setting system without a head pedestal, as well as an easy calibration system (see
Figure 4). The subjects each had their own seats with black bulkheads and individual laptops operating WebGazer. The subject’s gazing points were recorded as a two-dimensional coordinate pixel in the laptop, and we present the recorded pixel gazing points on the statement through the Photoshop program. There are various ways to record and present the gazing points with WebGazer. More details about WebGazer are found on its website at
https://webgazer.cs.brown.edu (accessed on 12 March 2021).
Eventually, the participants of each group were requested to see each statement assigned on their laptop monitors to test whether they paid significant attention to the information, and furthermore, whether they paid more attention to the more salient information than the less salient information. The eye-tracking experiment results are reported as follows. First, the representative pattern of the eyes on Statement-1 is shown in
Figure 5. Subjects’ eyes points in Group A were mostly located in the upper-left portion and the lower-right parts, meaning that their attention started in the upper-left part and moved toward the lower-right part. The blue points became darker as the subjects’ eyes focused on them more. Therefore, it was found that the subjects gave more attention to the total payment amount located in the upper left and the payment details in the lower right, which was consistent with the answers from before the survey. However, it appears that few residents’ eyes fell on the resident comparison part, which was in the lower-left-most side. We deduced that residents normally did not see the resident comparison information in their monthly utility statements.
Next, the representative sample of eyes on Statement-2 is displayed in
Figure 6. It is found that significant attentions were paid to the neighbor-comparison information although they were not many, which is different from the
Figure 5 showing no attentions to the information. Thus, it is argued that some subjects may have perceived the information when the information is much salient. The moving pattern of the eyes was similar in that most of the subjects’ eyes gazed at the upper-left total payment and the lower-right payment details.
Furthermore, to assess the difference in the average times of eye-gazing points among the sections of major information in the statement, we set up seven sections in Statement-1 and eight sections in Statement-2. We measured the average times of subjects’ eye-gazing points for each section and conducted variance analysis. We defined the eye-gazing points in this paper as a fixation which was characterized by relative immobility (low position variance), whereas a saccade was distinguished by a rapid change of position (high position variance) based on a position-variance method. This paper could objectively detect fixation and saccade by selecting an appropriate threshold value for position variance based on the method [
16] (p. 190). Therefore, each subject’s fixation on the information was measured by the average time for the eye-gazing points within the identically sized sections.
Although 54 subjects (26 subjects in Group A and 28 subjects in Group B) were the initial participants in the eye-tracking experiment, we collected significant recorded results from 20 subjects in Group A and 17 subjects in Group B, since we eliminated the results from the subjects who violated our experimental rules and the results technically not saved by the system. The subjects were required to see the statement displayed on the monitor in their usual ways, but they were prohibited from turning their heads and doing something else before their experimental sessions were completed. Five subjects in Group A and three subjects in Group B belonged in the violation cases. Additionally, several subjects’ results were eliminated when the subjects failed the calibration tasks. Two subjects in Group A and six subjects in Group B belonged in the calibration case. Finally, the experimental results from two subjects in Group B were not saved in the WebGazer.js system due to unidentified technical problems.
The average times of the subjects’ eye-gazing points are summarized in
Figure 7 and
Figure 8 for each statement with equally divided areas of interest (AOIs). Statement-1 had seven AOI sections, and Statement-2 had eight AOI sections, employing similar numbers of AOIs as prior studies, such as [
20], which considered nine AOIs. For Statement-1, the AOI of Section 6, showing payment details for items such as household-level electricity, water, and broadcasting fees, took the longest time at 347 milliseconds (hereafter ms). Other payment details in Sections 5 and 7 and the total utility payment in Section 1 took the next-most attention at 130 ms, 124 ms, and 109 ms, respectively. However, the most important finding was that the neighbor comparison information located in the AOI of Section 4 in Statement-1 only commanded scant attention at 55 ms while the information located in Section 5 for Statement-2 took considerably greater attention at 277 ms, which shows how important salience of the information is for attracting people’s interest.
These eye-tracking experiment results on the monthly utility statement are consistent with the well-established attention deployment argument that attention can be voluntarily controlled by the current goals of the observer (so-called goal-driven attention) and involuntarily driven by the physical salience of stimuli (so called stimulus-driven attention). In general, the attention of the residents was driven by a goal, because the attention in both Statement-1 and Statement-2 moved from the upper left to the lower right, as people usually read a book to find the gist of the information in it. The gist of the information in the statement they wanted to obtain was the payment information, because they paid sufficiently significant attention to the AOI sections containing payments for far more than 100 ms of gazing time, where 100 ms is the criterion of time for obtaining the gist of the information in a print document [
14]. However, stimulus-driven attention happened when the size of the neighbor comparison information was four times larger in Statement-2 than in Statement-1. The AOI of Section 5 in Statement-2 (see
Figure 8) attracted attention for 277 ms, but the AOI of Section 4 in Statement-1 (See
Figure 7) attracted only 55 ms worth of attention. This finding is explained by the conclusion that a combination of these two types determines how attention is deployed in most cases [
16] (p. 125).
Regarding the results shown in
Figure 7 and
Figure 8, a question can be arisen: Do exactly same contents in the statement attract significantly different attentions? For example, the total payment per household content displayed in Section 7 for Group A attracted 124 ms of attention, but the same content displayed in Section 8 for Group B attracted only 66 ms of attention. The answer is no. The differences in attention times for the same content did not indicate different interests in the same content. The total payment per household information is displayed in three different locations over and over in a statement because it is pecuniary. As shown in
Figure 7 and
Figure 8, Group A could see the total payment in the AOIs of Sections 1, 2, and 7, and Group B could see it in Sections 1, 2, and 8. For the AOI of Section 1, there was no significant difference in attention times between Group A at 109 ms and Group B at 135 ms. For Section 2, Group A’s gazing time was 49 ms, which was less than Group B’s 155 ms, whereas the time of attention of Group A to the last AOI section was 124 ms, which was more than Group B’s 66 ms. Thus, Group A and Group B had similar amounts of interest in the total payment information, although they saw a different location to check the information.
Using data on the time of fixation from the eye-tracking experiments, we made variance analyses to assess whether the times were statistically different across different sections.
Table 2 and
Table 3 show the results for Statement-1 and Statement-2, respectively. A low
p-value confirmed the statistically different fixation times for each section.