Determining topic interest and/or topic expertise and generating recommendations based on topic interest and/or expertise

1. A method for generating a topic ontology model and using the topic ontology model for providing recommendations, the method comprising:

obtaining data representing accounts that are associated with respective topics, each of the accounts being an account of a social network platform, each of the respective topics being an expertise topic of the account, and each of the accounts being associated with two or more respective topics;

ranking the topics associated with each account on a per account basis such that every account is associated with a ranked list of topics;

limiting the size of each ranked list to a top N topics, wherein N is initially a predetermined integer greater than one;

determining how many of the accounts are associated with each of the topics in the ranked lists;

identifying all topics associated with a number of accounts that is less than a threshold number of accounts, and for each of the identified topics:

creating a child node for the identified topic;

determining a parent node for the child node, including determining a highest ranked topic other than the identified topic in each of the ranked lists in which the identified topic appears and creating a parent node for a most frequently occurring topic among the highest ranked topics; and

generating a parent-child relationship between the parent node and the child node;

if N is greater than one, decrementing N by one and repeating the operations of limiting, determining, identifying and decrementing until N, before the decrementing, is equal to one;

when N is equal to one, combining the parent-child relationships generated in the generating operations to generate a topic ontology model;

after generating the topic ontology model, identifying, for a first account, a related topic from (i) interests of the account including a first interest of the first account and (ii) the topic ontology model, the first account being an account of the social network platform, the related topic not being one of the interests of the first account, wherein identifying the related topic includes finding the related topic by finding in the topic ontology model a first node corresponding to the first interest of the account and a related node connected closely to the first node, wherein the related node is connected closely by virtue of being a direct parent of the first node, a direct grandparent of the first node, or a child of the direct parent or the direct grandparent;

generating a recommendation for the first account based on the related topic; and

providing the recommendation to the first account.

2. The method of claim 1 , wherein obtaining data representing accounts that are associated with respective topics comprises obtaining data that associates accounts with respective normalized sets of topics, each normalized set including exactly two topics.

3. The method of claim 1 , wherein the ranking of topics for each account indicates a relative strength of expertise of the account for the topics associated with the account.

4. The method of claim 1 , wherein the threshold number of accounts is four.

5. The method of claim 1 , wherein the value of N is initially ten.

6. The method of claim 1 , wherein:

the recommendation is a recommendation to follow a second account that has the related topic as an expertise topic of the second account.

7. The method of claim 1 , wherein:

providing the recommendation comprises providing a platform message to the first account, wherein the platform message is from a third account that the first account is not following or otherwise related to, and wherein the third account has the related topic as an expertise topic of the third account.

8. A non-transitory computer readable medium comprising instructions that, when executed by a computer processor, perform a method for generating a topic ontology model and using the topic ontology model for providing recommendations, the method comprising:

obtaining data representing accounts that are associated with respective topics, each of the accounts being an account of a social network platform, each of the respective topics being an expertise topic of the account, and each of the accounts being associated with two or more respective topics;

ranking the topics associated with each account on a per account basis such that every account is associated with a ranked list of topics;

limiting the size of each ranked list to a top N topics, wherein N is initially a predetermined integer greater than one;

determining how many of the accounts are associated with each of the topics in the ranked lists;

identifying all topics associated with a number of accounts that is less than a threshold number of accounts, and for each of the identified topics:

creating a child node for the identified topic;

determining a parent node for the child node, including determining a highest ranked topic other than the identified topic in each of the ranked lists in which the identified topic appears and creating a parent node for a most frequently occurring topic among the highest ranked topics; and

generating a parent-child relationship between the parent node and the child node;

if N is greater than one, decrementing N by one and repeating the operations of limiting, determining, identifying and decrementing until N, before the decrementing, is equal to one;

when N is equal to one, combining the parent-child relationships generated in the generating operations to generate a topic ontology model;

after generating the topic ontology model, identifying, for a first account, a related topic from (i) interests of the account including a first interest of the first account and (ii) the topic ontology model, the first account being an account of the social network platform, the related topic not being one of the interests of the first account, wherein identifying the related topic includes finding the related topic by finding in the topic ontology model a first node corresponding to the first interest of the account and a related node connected closely to the first node, wherein the related node is connected closely by virtue of being a direct parent of the first node, a direct grandparent of the first node, or a child of the direct parent or the direct grandparent;

generating a recommendation for the first account based on the related topic; and

providing the recommendation to the first account.

9. The non-transitory computer readable medium of claim 8 , wherein obtaining data representing accounts that are associated with respective topics comprises obtaining data that associates accounts with respective normalized sets of topics, each normalized set including exactly two topics.

10. The non-transitory computer readable medium of claim 8 , wherein the ranking of topics for each account indicates a relative strength of expertise of the account for the topics associated with the account.

11. The non-transitory computer readable medium of claim 8 , wherein the threshold number of accounts is four.

12. The non-transitory computer readable medium of claim 8 , wherein the value of N is initially ten.

13. The non-transitory computer readable medium of claim 8 , wherein:

the recommendation is a recommendation to follow a second account that has the related topic as an expertise topic of the second account.

14. The non-transitory computer readable medium of claim 8 , wherein:

providing the recommendation comprises providing a platform message to the first account, wherein the platform message is from a third account that the first account is not following or otherwise related to, and wherein the third account has the related topic as an expertise topic of the third account.

15. A system for generating a topic ontology model and using the topic ontology model for providing recommendations, the system comprising:

a social network platform implemented on one or more computers and configured to connect to a plurality of client devices, each client device being associated with an account managed by the social network platform; and

an account repository comprising a plurality of accounts which are members of the social network platform,

the social network platform being configured to generate a topic ontology model and using the topic ontology model to provide recommendations to the plurality of accounts by:

obtaining data representing accounts that are associated with respective topics, each of the accounts being an account of a social network platform, each of the respective topics being an expertise topic of the account, and each of the accounts being associated with two or more respective topics;

ranking the topics associated with each account on a per account basis such that every account is associated with a ranked list of topics;

limiting the size of each ranked list to a top N topics, wherein N is initially a predetermined integer greater than one;

determining how many of the accounts are associated with each of the topics in the ranked lists;

identifying all topics associated with a number of accounts that is less than a threshold number of accounts, and for each of the identified topics:

creating a child node for the identified topic;

determining a parent node for the child node, including determining a highest ranked topic other than the identified topic in each of the ranked lists in which the identified topic appears and creating a parent node for a most frequently occurring topic among the highest ranked topics; and

generating a parent-child relationship between the parent node and the child node;

if N is greater than one, decrementing N by one and repeating the operations of limiting, determining, identifying and decrementing until N, before the decrementing, is equal to one;

when N is equal to one, combining the parent-child relationships generated in the generating operations to generate a topic ontology model;

after generating the topic ontology model, identifying, for a first account, a related topic from (i) interests of the account including a first interest of the first account and (ii) the topic ontology model, the first account being an account of the social network platform, the related topic not being one of the interests of the first account, wherein identifying the related topic includes finding the related topic by finding in the topic ontology model a first node corresponding to the first interest of the account and a related node connected closely to the first node, wherein the related node is connected closely by virtue of being a direct parent of the first node, a direct grandparent of the first node, or a child of the direct parent or the direct grandparent;

generating a recommendation for the first account based on the related topic; and

providing the recommendation to the first account.

16. The system of claim 15 , wherein obtaining data representing accounts that are associated with respective topics comprises obtaining data that associates accounts with respective normalized sets of topics, each normalized set including exactly two topics.

17. The system of claim 15 , wherein the ranking of topics for each account indicates a relative strength of expertise of the account for the topics associated with the account.

18. The system of claim 15 , wherein the threshold number of accounts is four.

19. The system of claim 15 , wherein the value of N is initially ten.

20. The system of claim 15 , wherein:

the recommendation is a recommendation to follow a second account that has the related topic as an expertise topic of the second account.

21. The system of claim 15 , wherein:

providing the recommendation comprises providing a platform message to the first account, wherein the platform message is from a third account that the first account is not following or otherwise related to, and wherein the third account has the related topic as an expertise topic of the third account.