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Improved Cooking Stoves (ICSs) represent the most commonly promoted solution to alleviate the burden associated with the use of traditional biomass in a short-term perspective. However, criticism is raising about the methodologies used for assessing their performance, with a particular focus on laboratory-based testing protocols. One of the key weaknesses of current protocols consists in the inaccurate and biased approach adopted for reporting and statistically analysing test results, which can lead to misleading conclusions about the actual improvements ensured by ICSs. This study proposes a robust procedure to deal with the statistical analysis of small sample sizes, and subsequently verify it through its application to an experimental comparison – based on the Water Boiling Test – between three models of stove. The results show that the current practice based on 3 or 5 replicates often produces biases in the analyses, as at least 13 replicates might be needed to achieve reliable results. Moreover, the study shows how the t-test is in most cases improperly applied, while the proposed procedure allows to deal both with normally and of non-normally distributed data sets in a robust way. In one case, the apparent improvement of an ICS model as compared to the three-stone fire, is refuted by the application of our procedure. [ABSTRACT FROM AUTHOR]

Around 2.7 billion people rely on biomass fuelled inefficient devices for cooking and heating. Improved Cooking Stoves are promoted as a means to mitigate the economic, environmental and social implications of this practice. However, their diffusion is hindered by a number of factors, including in particular the lack of agreement on performance evaluation methodologies. Laboratory protocols are designed to give useful indications to cookstoves developers, in order to improve their performance under controlled conditions, while field protocols provide the assessment of real performance of a cookstove in a given context. However, due to high time and finance requirements of the latter, lab results are often used also for stoves selection, also because of a general misunderstanding regarding their correct utilisation. In this work, we provide a review of all lab protocols officially published to date, comparing conceptual and technical aspects. We find that no protocol takes into account all the relevant factors at once. As a result, lab tests carry little information about real field performance, and can be misleading regarding stoves optimisation. Therefore, the analysis reveals the need to define better standards, regarding: (i) repeatability, metrics and statistical analysis of results; (ii) burn sequences calibrated from time to time according to the specific user. [ABSTRACT FROM AUTHOR]