Improved Scoring of Satisfaction with Life Scale: Scoring of SWLS

Abstract

The Satisfaction with Life Scale (SWLS), a 5-item instrument with 7 response-categories per item, measures cognitive judgments of satisfaction with one's life using summative scoring where higher score implies higher life satisfaction. Discrete scores of SWLS using Likert-type items fail to satisfy equidistant property and do not consider distributions of item scores or scale scores. The paper gives an assumption-free method to convert item scores of SWLS to continuous scores following normal distribution and scale score is taken as sum of such normally distributed item scores. The proposed scores avoiding tied-scores facilitate better admissibility of arithmetic aggregation, meaningful comparisons, ranking, classification of individuals, assessment of progress/deterioration across time and undertaking parametric statistical analysis. In addition, it helps to assess changes in successive time-periods for an individual or a group of individuals, drawing of progress-paths and test of significance of progress or deterioration. Normality of proposed scores facilitates finding equivalent scores of several measures of life satisfactions with different scale formats and different score-ranges. Empirical illustration is given with hypothetical data. The proposed method is recommended to enhance the utilization of the SWLS for better measurement of satisfaction with life along with meaningful comparisons and inferences.