The use of continuous visual aid in the Best-Worst Method: an experiment with organic farmers in Paraguay

The adoption of organic agriculture in developing countries is a complex decision, as it involves considering various factors. Multicriteria decision analysis (MCDA) methods can be suitable for this type of decision, as evidenced in the literature. The Best-Worst Method (BWM) is an MCDA tool that has proven useful due to its simplicity and computational capability. This research aims to test the applicability of this method to a population with low levels of education and determine whether a questionnaire with a continuous visual aid, a slider, is more suitable than the standard questionnaire with digits. Moreover, it aims to ascertain which factors the consistency of the responses depends on. To achieve this, 217 farmers in Paraguay were surveyed, and the consistency of the results was measured. We found that the questionnaires with digits were more consistent. Then we investigated possible causes of these differences, observing that respondents with sliders tended to concentrate their responses more heavily on the extreme values of the scale (1 and 9). A regression analysis of the consistency values with respect to various socioeconomic variables found only a slight effect of total farm incomes to be significant. These results demonstrate the feasibility of using this sophisticated method in this type of population and suggest that using sliders is not advisable.