The present invention has been made to calculate objective variable distribution having high reliability irrespective of the section size in an explanatory variable in which frequency drastically changes to thereby obtain highly reliable importance degree.An importance degree calculation program comprises: a section generation step that receives, as an input, an instance set and an explanatory variable and uses the instance set to divide the explanatory variable into a plurality of sections to obtain a section set; a neighborhood instance set extraction step that uses the instance set, the section set, and a neighborhood instance number threshold to extract from across all sections a neighborhood instance set of each section in which the number of instances is greater than the neighborhood instance number threshold; an objective variable distribution calculation step that calculates an objective variable distribution from the neighborhood instance set of each section extracted by the neighborhood instance set extraction step; and an importance degree calculation step that calculates importance degree of each section from the objective variable distribution in each section obtained by the objective variable distribution calculation step and instance set.