Vote counting is a simple but limited method for synthesizing evidence from multiple evaluations, which involves simply comparing the number of positive studies (studies showing benefit) with the number of negative studies (studies showing harm). It does not take into account the quality of the studies, the size of the samples, or the size of the effect.
This example is take from the Abstract of a study conducted by Lewis and Pattanayak (2012) on the systematic review of the literature surrounding the adoption of Improved Cook Stoves (ICS) or cleaner fuels by households in developing countries. The extended analysis in included in the resource section below.
"Background: The global focus on improved cookstoves (ICSs) and clean fuels has increased because of their potential for delivering triple dividends: household health, local environmental quality, and regional climate benefits. However, ICS and clean fuel dissemination programs have met with low rates of adoption.
Objectives: We reviewed empirical studies on ICSs and fuel choice to describe the literature, examine determinants of fuel and stove choice, and identify knowledge gaps.
Methods: We conducted a systematic review of the literature on the adoption of ICSs or cleaner fuels by households in developing countries. Results are synthesized through a simple vote-counting meta-analysis.
Results: We identified 32 research studies that reported 146 separate regression analyses of ICS adoption (11 analyses) or fuel choice (135 analyses) from Asia (60%), Africa (27%), and Latin America (19%). Most studies apply multivariate regression methods to consider 7–13 determinants of choice. Income, education, and urban location were positively associated with adoption in most but not all studies. However, the influence of fuel availability and prices, household size and composition, and sex is unclear. Potentially important drivers such as credit, supply-chain strengthening, and social marketing have been ignored.
Conclusions: Adoption studies of ICSs or clean energy are scarce, scattered, and of differential quality, even though global distribution programs are quickly expanding. Future research should examine an expanded set of contextual variables to improve implementation of stove programs that can realize the “win-win-win” of health, local environmental quality, and climate associated with these technologies."
CHOOSING this option
Because this option does not take into account the quality of the studies or their size, it is generally better to use one of the other options for synthesizing evidence from multiple evaluations.
- Who Adopts Improved Fuels and Cookstoves?: A Systematic Review: is an example of a critical study where vote counting was used to evaluate the degree of adoption of improved fuels and cook stoves in developing countries.
Lewis JJ, Pattanayak SK, (2012) Who Adopts Improved Fuels and Cookstoves? A Systematic Review. Environ Health Perspect 120(5):doi:10.1289/ehp.1104194. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3346782/