8. A computer-implemented system for managing user attention by detecting hot topics in social indexes, comprising: an electronic database, comprising: articles of digital information and at least one social index comprising topics that each relate to one or more of the articles maintained for social indexing; and topic models matched to the digital information for each topic; a computer coupled with the electronic database and comprising a processor and memory within which code for execution by the processor is stored, further comprising: a training evaluation module configured to determine a form of training used to form the topic models; a training scoring module configured to generate a training score under example-based training for each topic chosen, comprising: a counting module configured to count numbers of positive and negative training examples, to set a training score in proportion to the positive and negative training examples numbers used; a characteristic word module configured to identify a number of characteristic words comprised in the articles relating to the topic; and an adjustment module configured to adjust the training score in proportion to the number of the characteristic words, wherein those topics with the higher training scores are favored and the topic models comprise at least one of fine-grained topic models and coarse-grained topic models; a classifier module configured to classify the articles under the topics using the topic models; an evaluation module configured to evaluate each of the topics in the social index for hotness, comprising: a plurality of electronically-stored time periods projected from the present; an article count evaluation module configured to evaluate counts of the articles appearing under each time period; a topic chooser module configured to choose the topics exhibiting a rising curve in the count of the articles that increases with recency during the time periods; and an analysis module configured to analyze quality of the articles within the topics chosen; and a user interface configured to visually present the topics comprised of the articles having acceptable quality.
8. A computer-implemented system for managing user attention by detecting hot topics in social indexes, comprising: an electronic database, comprising: articles of digital information and at least one social index comprising topics that each relate to one or more of the articles maintained for social indexing; and topic models matched to the digital information for each topic; a computer coupled with the electronic database and comprising a processor and memory within which code for execution by the processor is stored, further comprising: a training evaluation module configured to determine a form of training used to form the topic models; a training scoring module configured to generate a training score under example-based training for each topic chosen, comprising: a counting module configured to count numbers of positive and negative training examples, to set a training score in proportion to the positive and negative training examples numbers used; a characteristic word module configured to identify a number of characteristic words comprised in the articles relating to the topic; and an adjustment module configured to adjust the training score in proportion to the number of the characteristic words, wherein those topics with the higher training scores are favored and the topic models comprise at least one of fine-grained topic models and coarse-grained topic models; a classifier module configured to classify the articles under the topics using the topic models; an evaluation module configured to evaluate each of the topics in the social index for hotness, comprising: a plurality of electronically-stored time periods projected from the present; an article count evaluation module configured to evaluate counts of the articles appearing under each time period; a topic chooser module configured to choose the topics exhibiting a rising curve in the count of the articles that increases with recency during the time periods; and an analysis module configured to analyze quality of the articles within the topics chosen; and a user interface configured to visually present the topics comprised of the articles having acceptable quality. 11. A system according to claim 8 , wherein the processor and memory further comprise: a user metrics evaluation module configured to determine user metrics for the articles counted, comprising a read count module configured to count a number of times that each article appearing under each time period has been read; and a vote count module configured to find a number of votes on each article appearing under each time period has been read, wherein those topics comprised of the articles with the stronger user metrics are favored.