Walkability and the built environment: validation of the Neighborhood Environment Walkability Scale (NEWS) for urban areas in Mexico

The article gives the results of adjusting an abbreviated version of the Neighborhood Environment Walkability Scale to the situation in Mexico. The results were obtained through the application of 156 instruments to individuals selected through a probability sampling in the metropolitan area of Monterrey, in the state of Nuevo León, Mexico. The validation process was done over four stages; in the first stage, the questions were analyzed and the sampling was adjusted. In the second stage, a factor analysis was carried out; as the questions were Likert-scale type, we use principal components with a matrix of polychoric correlations. In the third stage, the ordinal and non-ordinal Cronbach Alpha coefficients were determined, as were the ordinal and non-ordinal McDonald Omega coefficients, showing that the non-ordinal ones tend to underestimate the level of reliability, as they assume that it is a continuous scale when in this case it is not; however, the literature shows that these coefficients have been the most used in the validation of this scale. Finally, the intervals of trust were calculated with the bootstrap method, with the goal of incorporating the sensitivity that the coefficients could imply in aspects such as the number of questions, intercorrelations between the questions, and the size of the sample. The results show that the ordinal Alpha and Omega coefficients for the three factors, as well as for the entire scale, will have robust values 95% of the time that the questionnaire is used.