Evaluating assumptions of scales for subjective assessment of thermal environments – do laypersons perceive them the way, we researchers believe?

Marcel Schweiker, Maíra André, Farah Al-Atrash, Hanan Al-Khatri, Rea Risky Alprianti, Hayder Alsaad, Rucha Amin, Eleni Ampatzi, Alpha Yacob Arsano, Elie Azar, Bahareh Bannazadeh, Amina Batagarawa, Susanne Becker, Carolina Buonocore, Bin Cao, Joon-Ho Choi, Chungyoon Chun, Hein Daanen, Siti Aisyah Damiati, Lyrian Daniel, Renata De Vecchi, Shivraj Dhaka, Samuel Domínguez-Amarillo, Edyta Dudkiewicz, Lakshmi Prabha Edappilly, Jesica Fernández-Agüera, Mireille Folkerts, Arjan Frijns, Gabriel Gaona, Vishal Garg, Stephanie Gauthier, Shahla Ghaffari Jabbari, Djamila Harimi, Runa Hellwig, Gesche Huebner, Quan Jin, Mina Jowkar, Jungsoo Kim, Nelson King, Boris Kingma, M. Donny Koerniawan, Jakub Kolarik, Shailendra Kumar, Alison Kwok, Roberto Lamberts, Marta Lask, M.C. Jeffrey Lee, Yoonhee Lee, Vanessa Lindermayr, Mohammadbagher Mahaki, Udochukwu Marcel-Okafor, Laura Marín-Restrepo, Anna Marquardsen, Francesco Martellotta, Jyotirmay Mathur, Isabel Mino-Rodriguez, Azadeh Montazami, Di Mou, Bassam Moujalled, Mia Nakajima, Edward Ng, Marcellinus Okafor, Mark Olweny, Wanlu Ouyang, Ana Lígia Papst de Abreu, Alexis Pérez-Fargallo, Indrika Rajapaksha, Greici Ramos, Saif Rashid, Christoph Reinhart, Ma. Isabel Rivera, Mazyar Salmanzadeh, Karin Schakib-Ekbatan, Stefano Schiavon, Salman Shooshtarian, Masanori Shukuya, Veronica Soebarto, Suhendri Suhendri, Mohammad Tahsildoost, Federico Tartarini, Despoina Teli, Priyam Tewari, Samar Thapa, Maureen Trebilcock, Jörg Trojan, Ruqayyatu Tukur, Conrad Voelker, Yeung Yam, Liu Yang, Gabriela Zapata-Lancaster, Yongchao Zhai, Yingxin Zhu, ZahraSadat Zomorodian

Abstract

People’s subjective response to any thermal environment is commonly investigated by using rating scales describing the degree of thermal sensation, comfort, and acceptability. Subsequent analyses of results collected in this way rely on the assumption that specific distances between verbal anchors placed on the scale exist and that relationships between verbal anchors from different dimensions that are assessed (e.g. thermal sensation and comfort) do not change. Another inherent assumption is that such scales are independent of the context in which they are used (climate zone, season, etc.). Despite their use worldwide, there is indication that contextual differences influence the way the scales are perceived and therefore question the reliability of the scales’ interpretation. To address this issue, a large international collaborative questionnaire study was conducted in 26 countries, using 21 different languages, which led to a dataset of 8225 questionnaires. Results, analysed by means of robust statistical techniques, revealed that only a subset of the responses are in accordance with the mentioned assumptions. Significant differences appeared between groups of participants in their perception of the scales, both in relation to distances of the anchors and relationships between scales. It was also found that respondents’ interpretations of scales changed with contextual factors, such as climate, season, and language. These findings highlight the need to carefully consider context-dependent factors in interpreting and reporting results from thermal comfort studies or post-occupancy evaluations, as well as to revisit the use of rating scales and the analysis methods used in thermal comfort studies to improve their reliability.

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