# Sensitivity Analysis of PROMETHEE II for the Evaluation of Environmental Websites
## 1 Introduction  
Several researchers have highlighted the advantages of parks and protected areas, not only for the protection of the environment but for the economic development of the areas as well [1]. Websites constitute the most common way to promote environmental information and promote a national park (NP) as an eco-touristic destination [2, 3]. The important role of the websites in the promotion of environmental information has been highlighted by several researchers [4, 5, 6, 7, 8]. The information available involves characteristics of a protected area (PA), the landscape, the culture, and generally its profile. The website can influence potential visitors and lead them to form an environmental attitude. However, the confirmation that the goals of the website are met can only be achieved through an evaluation experiment [9].  
For the evaluation of websites, several researchers have used criteria [10, 11] and some have used Multi-Criteria Decision Making (MCDM) models for combining these criteria in order to evaluate websites in different domains that are related to environmental content [9, 12, 13]. In some cases environmental websites have also been evaluated with the use of MCDM models [9, 14]. Previous work on the evaluation of websites of environmental content [14, 15, 16] has revealed the criteria and the weights of importance of these criteria using the Analytic Hierarchy Process (AHP) [17, 18].  
Taking into account the information provided in the previous experiments, in this paper we implement an evaluation experiment of the websites of the NPs in Italy. For this purpose, a combination of AHP with PROMETHEE II (Preference Ranking Organization METHod for Enrichment Evaluations II) [19, 20] is used. PROMETHEE has seen much use in environmental management, hydrology and water management, business and financial management, chemistry, logistics and transportation, manufacturing and assembly, energy management, and agriculture [21], but only once before for website evaluation [22]. ThePROMETHEE II outranking method was adopted for this evaluation experiment to aggregate the opinions of decision-makers that evaluate websites of environmental content. This method is software-driven, user-friendly, provides a direct interpretation of parameters, and analyzes the sensitivity of results.  
The combination of AHP with PROMETHEE II has been effectively used mainly in other domains and not for the evaluation of environmental websites (e.g., [23; 24; 25]). The only time that this combination has been used for the evaluation of environmental websites was with [PERSON] et al. [22], in which the websites of NPs of Greece and Italy were evaluated and compared. However, the main difference of the current work is that we focus on the sensitivity analysis of the application of PROMETHEE II for the evaluation of environmental websites. The sensitivity analysis can help one draw conclusions on the robustness of the method and the consistency of the results [26]. The robustness is also checked in comparison with other methods such as TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) [27], SAW (Simple Additive Weighting) [27] and WPM (Weighted Product Model) [28; 29].  
The main body of the paper is organized as follows: Section 2 presents the materials and methods. More specifically, its subsections present the websites of the PAs and their role in Italy, the criteria used for the evaluation as well as the steps of PROMETHEE II for the evaluation of environmental websites. In Section 3, the results of the application of PROMETHEE II, the comparison of that model with the three other MCDM models, and the sensitivity analysis, are presented. In Section 4, the discussion of this work is done by comparing this work with other similar experiments. In the last section, the conclusions drawn by this work are analyzed, the limitations are given and future work is announced.