# Personalizing Environmental Awareness through Smartphones Using AHP and PROMETHE II
## 1 Introduction
Analyzing the related literature, the majority of authors have mainly focused on three categories: (i) theoretical perspectives on environmental awareness, (ii) measurement of people's environmental concern, and (iii) employing digital technologies for raising environmental awareness [1; 2; 4; 5; 8; 9; 10]. For the third category in particular, the authors used mobile learning tools, digital games, social media, recommender systems, educational robotics, digital storytelling tools, and extended reality to raise awareness about environmental issues. Other works presented user engagement methodologies in environmental education for awareness. In two recent studies [31; 32], it was emphasized that the need to develop software to increase people's awareness of environmental issues is still profound. However, based on the above works, the authors have not incorporated sufficiently intelligent techniques to further promote the environmental awareness of people by offering a user-centered experience to them. [PERSON] and [PERSON] [5] have employed a multi-criteria decision-making (MCDM) method to build a recommender system. MCDM is a decision support methodology which is used to improve the credibility and reliability of the selected solution. MCDM aims to help the decision makers to find an optimal solution in accordance with the criteria in question, as for example in [33; 34; 35; 36; 37]. Analytic Hierarchy Process (AHP) [38; 39] is one of the most popular MCDM theories, focusing on organizing and analyzing complex decisions; it provides a logical framework for a specific decision by quantifying its alternative options and criteria. In this paper, we show how AHP (Analytic Hierarchy Process) [37] can be effectively combined with PROMETHEE II (Preference Ranking Organization METHod for Enrichment Evaluations II) [40; 41] in a mobile application to further promote environmental awareness of users by offering personalized feedback to them based on their residence, habits, needs, age, and season. Selecting AHP over other MCDM methods is a simple process since it offers a validated way of quantifying the qualitative criteria of the alternatives and thus eliminates the subjectivity of the result [42]. However, in this method the pairwise comparison of options is quite complex; this method is not chosen in cases where the number of alternatives is large. Hence, AHP was chosen to be combined with PROMETHEE II. In more detail, PROMETHEE method is easy to use, software driven, offers an undeviating interpretation of parameters, and analyzes the sensitivity of results. PROMETHEE II is an excellent method for ranking and selecting among a limited set of alternative actions while observing several conflicting criteria [43]. Additionally, PROMETHEE II outranking method was embraced in this system to evaluate the alternative advice created by the system on the basis of the criteria acquired by the user model, rank the alternatives, and select the one with the higher value. In view of the above, we present how AHP can be utilized for calculating the weights of criteria and then combined with PROMETHEE II for evaluating and selecting the alternative proposal/advice that better fits the interests and needs of the user interacting with the system. It needs to be noted that the combination of AHP with PROMETHEE II has been effectively used in different domains (e.g., [44; 45; 46]), but never before for providing personalized advice for environmental awareness. In light of the foregoing, the scope of this paper is to combine AHP and PROMETHEE II to promote the environmental awareness of users in a personalized way through a smartphone. The mobile application holds a user model with information, such as place of living (e.g., urban, mountain, sea, etc. ), age and indexes of waste management, economy of natural resources, general environmental protection, and biodiversity. With the input of the user model, the system employs AHP and PROMETHEE II to deliver advice to users toward raising their environmental awareness.