The Likert-type scale is a widely used psychometric instrument for measuring attitudes, opinions, or perceptions in research contexts. It presents respondents with a series of statements accompanied by symmetrical response options, typically structured on a five-point scale ranging from “Strongly Disagree” to “Strongly Agree”. Each point on the scale represents a gradation of agreement or sentiment, allowing researchers to transform subjective responses into quantifiable data for statistical analysis and interpretation.

The Visual Analogue Scale (VAS) is a psychometric instrument used in research and clinical studies to measure the intensity of subjective experiences that cannot be objectively quantified using defined biomarkers, such as pain, fatigue, or mood. It typically consists of a 100 mm straight line with descriptive anchors at each end representing the extremes of the sensation (for example, “no pain” at one end and “the most severe pain imaginable” at the other). Respondents indicate their experience by marking a point on the line, and the distance from the lower anchor is measured and recorded as a continuous variable. VAS data can be analyzed using descriptive or inferential statistics, with the ordinal and non-linear properties of the scale requiring careful justification of the statistical methods applied.

A questionnaire is a structured instrument used in health research to systematically collect data on perceptions, behaviors, and health outcomes. It serves as a fundamental tool for capturing patient-reported outcomes, evaluating treatment effectiveness, and monitoring public health trends. Questionnaires can be administered in various formats, including paper-based, digital, or interactive systems, and must be carefully designed to ensure reliability, validity, and minimal bias. While validated questionnaires facilitate cross-study comparability, new instruments may be needed to address emerging health concerns or specific cultural contexts. Adhering to best practices in survey methodology allows researchers to maximize the utility of questionnaires, ensuring accurate, reproducible, and ethically sound health research.

Negative emotional states, such as stress, anxiety, and depression, are prevalent in university students. Personality traits have been shown to be associated with a wide range of behaviors in students, such as academic motivation, achievement, and social well-being. The aim of this study was to investigate the association between the Big Five personality traits and negative emotion states in university students in Taiwan. A cross-sectional study was conducted on 580 university students in Taiwan. Negative emotional states were evaluated using the Depression Anxiety Stress Scale-21 (DASS-21) and the Big Five personality traits were measured using the 48-item Big Five Inventory. A hierarchical linear regression analysis was used to assess the factors associated with DASS-21 scores. Neuroticism (standardized beta [std. β] = 0.45, p < 0.001) and openness (std. β = 0.12, p = 0.003) were significantly associated with DASS-21 scores, while agreeableness (std. β = −0.10, p = 0.007) was significantly and inversely associated with DASS-21 scores. Personality traits could be used to identify students at risk of negative emotional states and to undertake appropriate preventive strategies.

Background: The International Journal of Environmental Research and Public Health (IJERPH), a peer-reviewed, open-access journal launched in 2004 by the Multidisciplinary Digital Publishing Institute (MDPI), experienced rapid growth due to its broad scope and accessibility. However, its delisting from Clarivate’s Web of Science in 2023, prompted by concerns over editorial scope, marked a pivotal shift in its trajectory.Aim of the study: This study conducted a bibliometric analysis of IJERPH’s publication output from 2004 to 2023, examining citation trends, authorship networks, geographical contributions, and thematic shifts to assess its scientific influence and the impact of its removal from Web of Science.Materials and methods: Original research articles published in IJERPH between January 1, 2004, and December 31, 2023, were retrieved from the Scopus database. Bibliometric indicators, including publication trends, citation impact, collaboration networks, and thematic evolution, were analyzed using Bibliometrix 4.1 and VOSviewer 1.6.20. Results: The analysis revealed a sharp increase in publication volume, particularly after 2019, with China, the United States, Spain, and Taiwan emerging as leading contributors. The journal’s output peaked in 2022, driven by a surge in COVID-19-related studies. Thematic analysis identified four key research clusters: (1) COVID-19 and mental health, (2) physical activity and obesity, (3) public health and environmental risk, and (4) quality of life and health promotion.Conclusions: This bibliometric analysis showed IJERPH’s rapid expansion and global reach, particularly after 2019. However, its delisting from Web of Science in 2023 disrupted citation momentum, reduced its appeal as a publishing venue, and raised concerns regarding its long-term visibility. This case illustrates the challenges of balancing rapid growth in open-access publishing with maintaining trust within the scientific community.