A data analysis device that analyzes data having a record including an objective variable and a plurality of explanatory variables includes a node generating unit that generates a node specified by a condition of the explanatory variable on the basis of the objective variable and the explanatory variable of the record and associating the record with the node, an evaluation value generating unit that generates a proportion of the number of records whose target value is the objective variable among a plurality of records associated with the node as an evaluation value, and a parameter extracting unit that selects a node on the basis of the evaluation value and extracts and outputs the condition of the explanatory variable related to the selected node.
Please help me write a proper abstract based on the patent claims. CLAIM: 1. A data analysis device that analyzes data having a record including an objective variable and a plurality of explanatory variables, comprising: a node generating unit that generates a node specified by a condition of the explanatory variable on the basis of the objective variable and the explanatory variable of the record and associating the record with the node; an evaluation value generating unit that generates a proportion of the number of records whose target value is the objective variable among a plurality of records associated with the node as an evaluation value; and a parameter extracting unit that selects a node on the basis of the evaluation value and extracts and outputs the condition of the explanatory variable related to the selected node. 2. The data analysis device according to claim 1, wherein the evaluation value generating unit sets a value which is able to be had by the objective variable as the target value and generates the evaluation value for each target value for each node. 3. The data analysis device according to claim 2, wherein the node extracting unit extracts the node for each target value. 4. The data analysis device according to claim 2, wherein the node extracting unit selects the node on the basis of the evaluation value of the node and a value related to the number of records of the node, and the value related to the number of records of the node is the number of records included in the node, the number of records included in the node in which the target value is the objective variable, and the proportion of the number of records included in the node in which the target value is the objective variable to the number of all records. 5. The data analysis device according to claim 1, wherein the node generating unit generates the node through decision tree analysis. 6. A data analysis method in a data analysis device that analyzes data having a record including an objective variable and a plurality of explanatory variables, comprising: generating, by the data analysis device, a node specified by a condition of the explanatory variable on the basis of the objective variable and the explanatory variable of the record and; associating, by the data analysis device, the record with the node; generating, by the data analysis device, a proportion of the number of records whose target value is the objective variable among a plurality of records associated with the node as an evaluation value; and selecting, by the data analysis device, a node on the basis of the evaluation value; and extracting and outputting, by the data analysis device, the condition of the explanatory variable related to the selected node. 7. The data analysis method according to claim 6, further comprising, setting, by the evaluation value generating unit, a value which is able to be had by the objective variable as the target value and generating the evaluation value for each target value for each node. 8. The data analysis method according to claim 7, further comprising, extracting, by the data analysis device, the node for each target value. 9. The data analysis method according to claim 7, further comprising: selecting, by the data analysis device, the node on the basis of the evaluation value of the node and a value related to the number of records of the node, wherein the value related to the number of records of the node is the number of records included in the node, the number of records included in the node in which the target value is the objective variable, and the proportion of the number of records included in the node in which the target value is the objective variable to the number of all records. 10. The data analysis method according to claim 6, further comprising, generating, by the data analysis device, the node through decision tree analysis.