A method for obtaining user traits. In response to a first kind of data of a target user not being sufficient to obtain a trait of the target user, a second kind of data of the target user is collected, where the first kind of data and the second kind of data are different kinds of data. Based on the second kind of data, one or more reference users similar to the target user are determined. Based on the first kind of data of the reference users, the trait of the target user is determined.
Please help me write a proper abstract based on the patent claims. CLAIM: 1. A computer-implemented method of obtaining user traits, the method comprising: in response to determining, by a computer, that a first kind of data of a target user is not sufficient to obtain a trait of the target user, collecting, by the computer, a second kind of data of the target user, wherein the first kind of data and the second kind of data are different kinds of data; determining, by the computer, based on the second kind of data, one or more reference users similar to the target user; and obtaining, by the computer, the trait of the target user based on the first kind of data of the reference users. 2. A method in accordance with claim 1, wherein the first kind of data of the target user includes textual data that describes a text associated with the target user, and wherein collecting the second kind of data of the target user comprises: collecting, by the computer, behavior data of the target user, the behavior data describing historical behaviors of the target user. 3. A method in accordance with claim 2, wherein determining one or more reference users similar to the target user comprises: determining, by the computer, users having similar behaviors to the target user as the reference users based on the behavior data. 4. A method in accordance with claim 1, wherein determining one or more reference users similar to the target user comprises: determining, by the computer, the reference users from seed users, wherein each of the seed users is a user having the first kind of data sufficient to obtain the trait. 5. A method in accordance with claim 4, wherein obtaining the trait of the target user based on the first kind of data of the reference users comprises: determining, by the computer, based on at least one of the first kind of data and the second kind of data of seed users in the reference users, a deviation degree between a first seed user in the reference users and other seed users in the reference users; and in response to determining that the deviation degree exceeds a predetermined threshold, adjusting, by the computer, a contribution of the first kind of data of the first seed user to the obtaining of the trait. 6. A method in accordance with claim 1, wherein determining one or more reference users similar to the target user comprises: determining, by the computer, the reference users from non-seed users, wherein each of the non-seed users is a user with the first kind of data insufficient to obtain the trait. 7. A method in accordance with claim 6, wherein obtaining the trait of the target user based on the first kind of data of the reference users comprises: grouping, by the computer, non-seed users in the reference users based on the second kind of data of the non-seed users in the reference users; aggregating, by the computer, the first kind of data of the non-seed users in the reference users based on the grouping; and obtaining, by the computer, the trait based on the aggregated first kind of data. 8. A method in accordance with claim 1, further comprising: in response to determining, by the computer, that the first kind of data of the target user is sufficient to obtain the trait of the target user, storing, by the computer, the first kind of data of the target user for use in obtaining the trait of a further user. 9. A computer system for obtaining traits, the computer system comprising: one or more computer processors, one or more computer-readable storage media, and program instructions stored on one or more of the computer-readable storage media for execution by at least one of the one or more processors, the program instructions comprising: program instructions, in response to determining, by a computer, that a first kind of data of a target user is not sufficient to obtain a trait of the target user, to collect a second kind of data of the target user, wherein the first kind of data and the second kind of data are different kinds of data; program instructions to determine, based on the second kind of data, one or more reference users similar to the target user; and program instructions to obtain the trait of the target user based on the first kind of data of the reference users. 10. A computer system in accordance with claim 9, wherein the first kind of data of the target user includes textual data that describes a text associated with the target user, and wherein program instructions to collect the second kind of data of the target user comprise: program instructions to collect behavior data of the target user, the behavior data describing historical behaviors of the target user. 11. A computer system in accordance with claim 10, wherein program instructions to determine one or more reference users similar to the target user comprise: program instructions to determine users having similar behaviors to the target user as the reference users based on the behavior data. 12. A computer system in accordance with claim 9, wherein program instructions to determine one or more reference users similar to the target user comprise: program instructions to determine the reference users from seed users, wherein each of the seed users is a user having the first kind of data sufficient to obtain the trait. 13. A computer system in accordance with claim 12, wherein program instructions to obtain the trait of the target user based on the first kind of data of the reference users comprise: program instructions to determine, based on at least one of the first kind of data and the second kind of data of seed users in the reference users, a deviation degree between a first seed user in the reference users and other seed users in the reference users; and program instructions, in response to determining that the deviation degree exceeds a predetermined threshold, to adjust a contribution of the first kind of data of the first seed user to the obtaining of the trait. 14. A computer system in accordance with claim 9, wherein program instructions to determine one or more reference users similar to the target user comprises: program instructions to determine the reference users from non-seed users, wherein each of the non-seed users is a user with the first kind of data insufficient to obtain the trait. 15. A computer system in accordance with claim 14, wherein program instructions to obtain the trait of the target user based on the first kind of data of the reference users comprise: program instructions to group non-seed users in the reference users based on the second kind of data of the non-seed users in the reference users; program instructions to aggregate the first kind of data of the non-seed users in the reference users based on the grouping; and program instructions to obtain the trait based on the aggregated first kind of data. 16. A computer system in accordance with claim 9, further comprising: program instructions, in response to determining that the first kind of data of the target user is sufficient to obtain the trait of the target user, to store the first kind of data of the target user for use in obtaining the trait of a further user.