Designing an Application to Support Waste Identification and Disposal Decisions among International Students: A Service Design Approach

According to the Global Waste Index 2025, South Korea generates approximately 438 kg of waste per capita annually and recycles 236 kg, ranking among the top countries in waste recycling and resource recovery [1]. One factor contributing to this performance is the Volume-Based Waste Fee System (VBWF), introduced in 1995, which encourages waste reduction through mandatory separation into categories such as plastics, paper, glass, cans, food waste, and general waste [2]. For residents unfamiliar with the system, however, these detailed rules can be difficult to follow. International students, in particular, often experience uncertainty when identifying the correct disposal category, highlighting the need for more accessible, user-centred support. This issue is becoming increasingly significant as the number of international students in Korea reached 253,434 in 2025 [3], and these students must adapt not only to academic environments but also to unfamiliar everyday systems [4]. At the Institute of Korean Language Education (IKLE), categorized white bins and labels are currently provided to support correct disposal behaviour. However, preliminary observation (Section 4.1) indicated that students still struggle to classify waste correctly because Korean disposal rules may differ from those in their home countries. Time pressure between classes may further intensify this difficulty. This study therefore assumes that the problem lies not in environmental awareness but in making a decision at the waste station, where uncertainty about categories can lead to sorting errors.

Previous research has examined waste-separation behaviour among university students and found that the presence of waste bins alone does not guarantee correct classification [5]. The study also suggested that the perceived value of sorting behaviour may influence participation. A recent Korean study proposed a waste-sorting education application for foreign residents and incorporated surveys, interviews, personas, customer journey maps, multicultural design elements, and interactive functions [6]. However, this approach focuses primarily on education before disposal, and a more focused design opportunity remains at the moment of disposal itself. In particular, international students have a specific institutional context, limited time between classes, and varying levels of familiarity with Korean waste regulations. The purpose of this study is to design an application that supports international students' waste-sorting decisions at the point of disposal through a service design method. The study specifically aims to: .Identify waste disposal challenges faced by international students. .Determine when digital support is most needed during disposal. .Design a fast, culturally responsive waste-sorting app.

Lee and Paik [2] observed that waste-management attitudes and environmental awareness influence recycling behaviour in Korea. However, positive attitudes alone do not guarantee correct waste classification. In an experimental study of university students in Indonesia, although many participants attempted to separate waste, incorrect classification remained common, and the presence of waste bins alone did not determine correct sorting [5]. Similarly, a study of university students in the Netherlands found that only just over half of the waste was correctly sorted despite students' high intentions to separate waste, and that providing additional information did not significantly improve sorting behaviour [8]. Foreign residents in Korea likewise experience difficulties understanding disposal categories and regulations, resulting in uncertainty during the sorting process [6]. Therefore, as awareness and positive attitudes alone do not ensure correct disposal, additional support is needed to translate intention into action. Fogg's Behavior Model offers a useful lens for this intention–action gap: a behaviour occurs only when motivation, ability, and a prompt converge at the same moment [9]. For international students, the motivation to sort correctly appears to be present, whereas the ability to classify unfamiliar items under Korean rules is limited at the moment of disposal. This suggests that support should be provided not only before the act of sorting but also at the point of decision, at the very moment of disposal. This study addresses this challenge by providing international students with immediate classification guidance at the waste station through a digital service.

Li and Lee (2025) responded to post-COVID growth in Korea's foreign population by proposing a waste sorting education app for foreign residents, whose difficulties stemmed from Korea's complex system, differing home-country practices, and limited cultural understanding. Comparing national sorting methods and icons, reviewing existing recycling apps, and surveying and interviewing foreign residents, they found needs differ by residence length: short-term residents face language barriers and information gaps, long-term residents struggle with complex regulations [6]. However the research does not exclusively isolate international students who can fall both in the short and long term residents categories. As it has been established that positive attitudes do not guarantee correct sorting; behaviour depends on in-the-moment execution, not knowledge alone, the present research therefore develops an application supporting international students at the decision stage, translating knowledge into correct action when it matters, which is providing immediate classification guidance and decision support during the waste-disposal process.

Waste management, specifically waste sorting, can be understood as a service involving users, waste bins, labels, building rules, information, and feedback mechanisms. Service design is a human-centred approach that examines user experiences across multiple service touchpoints [9] and is therefore suitable for addressing this problem. To understand users, define the main problem, develop solutions, and refine them through prototyping, this study adopts the Double Diamond framework [10]. Irbīte and Strode [11] describe the Double Diamond as a four-stage design-thinking model consisting of Discover, Define, Develop, and Deliver, organized across two connected diamonds that represent the movement between expanding and narrowing the design space. Within this framework, this study uses customer journey mapping to connect user experiences with service requirements.

The Discover and Define stages examined existing research, observed student behaviour at the IKLE waste station, and collected survey data on nationality, residence duration, Korean-language ability, previous waste-sorting experience, and disposal difficulties. The findings were then synthesized into a customer journey map to identify repeated pain points, decision barriers, and the main point for service intervention. In the Develop stage, the identified problems were translated into service requirements.

To discover and define the waste-sorting problem of international students, a preliminary user study was conducted through field observation and an online survey. Field observations were carried out at IKLE from 17 to 21 August 2025. A total of five (5) 1-hour observation sessions were conducted over a period of 5 days , covering about 140 students. Observations were recorded through photographs, taken without identifying individuals, and the observer's written field notes. The observations revealed that students often paused at waste stations to read labels, hesitated before disposing of items, or quickly discarded waste without confirming the correct category, particularly during busy periods after class. To investigate these behaviours further, an online survey was conducted from 2 to 6 September 2025 with 25 international students aged between 20 and 30 years old. The participants included 20 females and 5 males from Vietnam, China, the United States, Russia, India, Pakistan, Bangladesh, Nigeria, Brazil, Colombia, Albania, and Kyrgyzstan. The survey examined students’ confidence in waste sorting, sources of confusion, disposal challenges, previous disposal experiences, and willingness to use a digital support service. The findings showed that only 20% of participants felt confident in sorting waste correctly, while 100% reported experiencing confusion when classifying waste in Korea. Participants identified too many waste categories (12 responses) and unclear instructions (11 responses) as the main challenges, while 80% admitted to previously disposing of waste incorrectly due to uncertainty. Furthermore, 68% expressed willingness to use a waste-sorting support application. Table 1 summarizes the survey and observation findings and the design requirements derived from them.

These findings indicate that the primary issue is not a lack of environmental awareness or motivation, but difficulty identifying the correct disposal category at the point of disposal. Based on these insights, a customer journey map was developed to visualize the waste-disposal experience of international students (Figure 2). By mapping users' actions, thoughts, emotions, and pain points throughout the process, the journey map highlights moments of uncertainty and identifies opportunities for service intervention. The decision-making stage, when students must classify an item quickly despite limited certainty, was identified as the main intervention point.

The design implications in Table 1 were consolidated into six service requirements. As a means of addressing them, a digital service was proposed, based on the willingness of most participants (68%) to use an app. First, because students experienced time pressure and needed guidance before disposal, the service had to be accessible directly at the waste station; this led to QR access at the waste station, which also reflects participants' preference for a QR guide. Second, the widespread confusion and the difficulty with specific categories such as general waste and plastics indicated that users needed to check individual items rather than the entire sorting system, which led to item search. Third, to provide clear decision support while simplifying information, the service presents only the category relevant to the selected item, resulting in category-specific guidance. Fourth, because correct disposal under Korean rules often requires items to be prepared, for example by emptying or rinsing containers, preparation instructions were included to reduce incorrect disposal. Fifth, unclear instructions and participants' preference for multilingual support led to language support. Finally, the low level of confidence suggested that users would benefit from gradually building their sorting knowledge beyond a single disposal decision, which led to general waste-management tips. Finally, the low level of confidence suggested that users would benefit from gradually building their sorting knowledge beyond a single disposal decision, which led to general waste-management tips. The proposed service, BARO, derived from the Korean word '바로', meaning 'right away', is a QR-based web application that helps international students identify the correct disposal category for a specific waste item at the waste station. To guide the interface design, four design principles were established from the service requirements. First, the service should be fast, because students may be between classes. Second, it should use the actual disposal rules of the building rather than generic national information. Third, it should minimize interaction by avoiding mandatory login and unnecessary navigation. Fourth, it should support international students through plain language and visual explanations. The service operates through the following sequence (Figure 3): The user opens the app and scans the QR code on the waste bin, which identifies the waste station and its disposal rules. The user scans the waste item to be discarded with the smartphone camera. The app identifies the waste category and displays disposal and preparation instructions. The user disposes of the item in the correct bin. If needed, the user checks the waste guide for detailed category instructions. In the prototype, waste item recognition was simulated rather than implemented

The interface was designed according to the four design principles described in Section 4.2 and prototyped in Figma. It consists of four main screens: the QR scan screen, the waste item scan screen, the decision-support screen, and the waste guide screen (Figure 4).

The QR scan screen is the entry point of the service. When the user opens the app, the camera view guides them to scan the QR code on the waste station, which loads the disposal rules of that building. This reflects the principle of using building-specific rules rather than generic national information. The waste item scan screen allows the user to point the smartphone camera at the item to be discarded. Language options are provided at the top of the screen so that users can receive guidance in their preferred language. If a QR code is unavailable, users can browse the waste guide directly. By reducing the process to two scans without login or additional navigation, these screens address time pressure and minimize the number of steps needed to reach an answer. The decision-support screen presents the recommended disposal category, an image or name of the scanned item, and short preparation instructions. The screen avoids presenting lengthy regulatory explanations before the user disposes of the item; detailed information is available in the waste guide, while the main screen prioritizes the category and the immediate preparation steps. The waste guide screen shows the waste categories, such as plastics, food waste, general waste, paper, glass, electronic waste, and hazardous waste, together with the kinds of items that fall under each and common disposal rules. This creates a lightweight learning loop through which users can gradually gain insight into the sorting system beyond a single disposal decision. A pop-up modal additionally provides daily waste-sorting tips.

A preliminary usability test was conducted with 20 of the 25 participants who completed the initial survey, representing 80% of the original participant group. Participants interacted with a Figma prototype of the proposed QR-based waste-sorting web application and evaluated its design, usefulness, ease of use, and problem-solving ability. The test was informed by the Technology Acceptance Model (TAM), particularly the concepts of perceived usefulness and perceived ease of use. Perceived usefulness refers to whether users believe that the application can solve a practical problem, while perceived ease of use refers to whether the application can be understood and navigated without difficulty [10].

A preliminary usability evaluation was conducted with eight international students at IKLE to examine how prospective users perceived the BARO prototype. The evaluation consisted of three steps: introduction, prototype use, and a post-use questionnaire. First, the researcher explained the purpose and procedure of the evaluation. Participants were informed that the evaluation concerned the prototype. Second, participants freely explored the Figma prototype on a smartphone screen. They were asked to imagine that they were disposing of waste through the process provided by BARO: scanning the QR code on the waste bin, scanning a waste item, viewing the disposal category and preparation instructions, and browsing the waste guide. Because waste item recognition was simulated in the prototype, participants experienced the intended interaction sequence rather than actual recognition performance. Third, after using the prototype, participants rated three items developed for this study on a five-point Likert scale (1 = strongly disagree, 5 = strongly agree). Perceived usefulness concerned whether the service would help users sort waste correctly. User-friendly design concerned whether the interface was easy and comfortable to use. Problem-solving value concerned whether the service addressed the waste-sorting problem identified in Section 4.1. In addition, participants were invited to provide open-ended comments. The results were interpreted descriptively as indicators of participants' perceptions because each construct was measured with a single item and the sample was small.

Table 2 presents the distribution of ratings for the three evaluation items. Ratings of 4 or 5 were regarded as positive responses, and 1 or 2 as negative responses. Problem-solving value received the most positive responses, with five of the eight participants (62.5%) rating it 4 or 5. Perceived usefulness followed, with four participants (50.0%) responding positively and three rating it 3. User-friendly design received the fewest positive responses: three participants (37.5%) rated it 4 or 5, while half of the participants (four) rated it 3. Each item received one negative response, all from the same participant. In their open-ended comments, participants suggested three improvements: additional language options, integration with official municipal waste-management information, and a feedback feature for reporting unclear or missing disposal guidance.

The evaluation results can be interpreted in relation to the problem defined in Section 4.1 and the design decisions described in Section 4.2. First, problem-solving value received the most positive responses. This suggests that participants recognised the service as addressing their actual difficulty, namely uncertainty at the moment of disposal rather than a lack of environmental awareness, and thus indirectly supports the problem definition of this study. From the perspective of Fogg's Behavior Model [9], BARO was designed to respond to the gap between students' motivation and their ability at the point of disposal: the QR code on the waste bin acts as a prompt that reminds users to use the service at that moment, while waste item scanning and category-specific guidance support their ability to classify the item. Second, user-friendly design received the fewest positive responses, even though speed and minimal interaction were core design principles. One possible explanation is that the two-step scanning process, first the QR code on the bin and then the waste item, may have been perceived as involving more steps than expected. Another is that the need to open an app before use may weaken the intended immediacy of the service. These explanations remain tentative and should be examined through task-based usability testing that measures task completion time and errors. Third, participants' open-ended suggestions extend beyond the interface. While additional language options can be addressed at the screen level, integration with official municipal waste-management information and a feedback feature for reporting unclear guidance concern how disposal information is sourced, managed, and updated behind the interface. This indicates that BARO should be developed not only as an app but as a service system connecting users, building managers, and municipal waste-management information, consistent with the view of waste sorting as a service. Fourth, the participant who gave negative ratings across all three items noted that, although they had experienced difficulty in sorting waste correctly, they were not convinced that such an application could help.

This study proposed BARO, a QR-based mobile application that supports international students' waste-sorting decisions at the point of disposal. Field observation and a survey of 25 international students showed that the main difficulty was not a lack of environmental awareness but uncertainty in identifying the correct category at the moment of disposal. Based on these findings, six service requirements were derived and translated into a service combining QR access to building-specific rules, waste item scanning, category-specific guidance with preparation instructions, language support, and a waste guide. A preliminary evaluation with eight participants indicated that the service's problem-solving value was recognised most clearly, whereas its user-friendly design requires further improvement. The study contributes a point-of-disposal approach to waste-sorting support for international students. Whereas previous approaches have focused on educating users before disposal, this study shifts the focus to the moment when knowledge must be translated into action. It also shows how user research findings can be translated step by step into service requirements and interface design through a service design process. Future research should implement actual item recognition, test the service in a real disposal environment using task-based measures such as classification accuracy and task completion time, and extend the service to include the management and updating of disposal information. However, the evaluation involved only eight participants, used a prototype with simulated item recognition, and was based on hypothetical use. The findings are therefore best understood as an initial indication of users' perceptions, and further validation is needed before they can be extended to the broader population of international students or to actual disposal behaviour.

This research was supported by BK21 Four Service Design driven Social Innovation Educational Research Team in Dongseo University.