Techniques for predicting a user response to content are described. According to various embodiments, a configuration file is accessed, where the configuration file includes a user-specification of raw data accessible via external data sources and raw data encoding rules. In some embodiments, the raw data includes raw member data associated with a particular member and raw content data associated with a particular content item. Thereafter, source modules encode the raw data from the external data sources into feature vectors, based on the raw data encoding rules. An assembler module assembles one or more of the feature vectors into an assembled feature vector, based on user-specified assembly rules included in the configuration file. A prediction module performs a prediction modeling process based on the assembled feature vector and a prediction model, to predict a likelihood of the particular member performing a particular user action on the particular content item.
Please help me write a proper abstract based on the patent claims. CLAIM: 1. A method comprising: accessing a configuration file that includes a user specification of data accessible via external data sources and data encoding rules, the data including member data associated with a particular member and content data associated with a particular content item; encoding, using a plurality of source modules, the data from the external data sources into feature vectors, based on the data encoding rules; assembling, using an assembler module, one or more of the feature vectors into an assembled feature vector, based on user-specified assembly rules included in the configuration file; and performing, using a prediction module, a prediction modeling process based on the assembled feature vector and a prediction model, to predict a likelihood of the particular member performing a particular user action on the particular content item. 2. The method of claim 1, wherein the plurality of source modules includes a member source module configured to encode the member data into a member feature vector of the feature vectors, wherein the member data includes at least one of gender, age, location, industry, education, current job, experience, skills, and connections. 3. The method of claim 1, wherein the plurality of source modules includes a content source module configured to encode the content data into a content feature vector of the feature vectors, wherein the content data includes at least one of content format, content category, content keywords, content image, content targeting criteria, and content cost information. 4. The method of claim 1, wherein the plurality of source modules includes a context source module configured to encode context data into a context feature vector of the feature vectors, wherein the context data includes at least one of time, date, hour of day, day of week, hour of week, internet protocol (IP) address, user geo-location information, content item page position information, content item host page information, and content item rendering information. 5. The method of claim 1, wherein the plurality of source modules includes an impression frequency source module configured to encode impression frequency data into an impression frequency feature vector of the feature vectors, wherein the impression frequency data identifies a number of impressions of the particular content item by the particular member. 6. The method of claim 1, further comprising: determining that a particular one of the feature vectors is not available from a particular one of the source modules; determining that the particular feature vector may be ignored, based on a user-specified importance value associated with the particular feature vector; and inserting a user-specified substitute value associated with the particular feature vector into a portion of the assembled feature vector associated with the particular feature vector. 7. The method of claim 6, wherein the configuration file identifies the user-specified importance value and the user-specified substitute value associated with the particular feature vector. 8. The method of claim 1, further comprising: accessing user-specified transformation rules included in the configuration file; and modifying, using one or more transformation modules, one or more of the feature vectors into modified feature vectors, based on the user-specified transformation rules, wherein the assembler module assembles at least one of the modified feature vectors into the assembled feature vector. 9. The method of claim 8, wherein the one or more transformation modules include a subset transformation module configured to reduce a number of features included in a feature vector output by one of the source modules. 10. The method of claim 8, wherein the one or more transformation modules include an interaction transformation module configured to calculate a cross-product of two feature vectors output by two of the source modules. 11. The method of claim 8, wherein the one or more transformation modules include a numerical feature binning transformation module configured to transform a real-valued numerical feature in a feature vector output by one of the source modules into a set of binary-valued numerical features. 12. The method of claim 8, wherein a modified feature vector output from a first transformation module is input to a second transformation module, and wherein the second transformation module outputs a further modified feature vector. 13. The method of claim 1, wherein the content item is an advertisement, and wherein the user action is any one of a click response, a non-click response, a hover response, and a conversion response. 14. The method of claim 1, wherein the content item is included in a content feed, and wherein the user action is any one of a like response, a comment response, a share response, a rating response, a click response, a non-click response, and a hover response. 15. The method of claim 1, wherein the content item is an upgrade offer for upgrading a member account of the particular member, and wherein the user action is any one of a click response, a non-click response, a hover response, and a conversion response. 16. The method of claim 1, wherein the content item is a landing webpage for display after a previous webpage, and wherein the user action is one of a plurality of responses specific to the landing webpage. 17. The method of claim 1, wherein the prediction model is any one of a logistic regression model, a Naïve Bayes model, a support vector machines (SVM) model, a decision trees model, and a neural network model. 18. The method of claim 1, wherein the prediction module performs a training operation to refine coefficients of a logistic regression model, based on training set data comprising the assembled feature vector. 19. An apparatus comprising: a plurality of source modules configured to: access a configuration file that includes a user specification of data accessible via external data sources and data encoding rules, the data including member data associated with a particular member and content data associated with a particular content item; and encode the data from the external data sources into feature vectors, based on the data encoding rules; an assembler module configured to assemble one or more of the feature vectors into an assembled feature vector, based on user-specified assembly rules included in the configuration file; and a prediction module configured to perform a prediction modeling process based on the assembled feature vector and a prediction model, to predict a likelihood of the particular member performing a particular user action on the particular content item. 20. A non-transitory machine-readable storage medium having embodied thereon instructions executable by one or more machines to perform operations comprising: accessing a configuration file that includes a user specification of data accessible via external data sources and data encoding rules, the data including member data associated with a particular member and content data associated with a particular content item; encoding, using a plurality of source modules, the data from the external data sources into feature vectors, based on the data encoding rules; assembling, using an assembler module, one or more of the feature vectors into an assembled feature vector, based on user-specified assembly rules included in the configuration file; and performing, using a prediction module, a prediction modeling process based on the assembled feature vector and a prediction model, to predict a likelihood of the particular member performing a particular user action on the particular content item.