7. A computer-implemented method for determining term importance in a text content for information discovery and presentation, comprising: receiving a text content; tokenizing the text content into tokens as instances of terms, each token or term comprising one or more words or phrases; identifying a term with multiple token instances in the text content; identifying a first token instance of the term, wherein the first token instance is or is contained in a grammatical subject of a sentence; assigning a first importance value to the first token instance for being or being contained in a grammatical subject of a sentence; identifying a second token instance of the term, wherein the second token instance is or is in a non-subject portion of a sentence; assigning a second importance value to the second token instance for not being or not being contained in a grammatical subject of a sentence, wherein the second importance value is different from the first importance value; determining an importance measure for the term based on the sum of the first importance value and the second importance value; performing an action associated with the term if the importance measure is above a threshold, wherein the action comprises at least outputting an element associated with the term, displaying an element associated with the term, or using an element associated with the term for a computer-assisted operation associated with the text content including ranking a search result, wherein the element is selected from the group of elements consisting of at least the term, the importance measure, and a sentence or paragraph containing the term.
7. A computer-implemented method for determining term importance in a text content for information discovery and presentation, comprising: receiving a text content; tokenizing the text content into tokens as instances of terms, each token or term comprising one or more words or phrases; identifying a term with multiple token instances in the text content; identifying a first token instance of the term, wherein the first token instance is or is contained in a grammatical subject of a sentence; assigning a first importance value to the first token instance for being or being contained in a grammatical subject of a sentence; identifying a second token instance of the term, wherein the second token instance is or is in a non-subject portion of a sentence; assigning a second importance value to the second token instance for not being or not being contained in a grammatical subject of a sentence, wherein the second importance value is different from the first importance value; determining an importance measure for the term based on the sum of the first importance value and the second importance value; performing an action associated with the term if the importance measure is above a threshold, wherein the action comprises at least outputting an element associated with the term, displaying an element associated with the term, or using an element associated with the term for a computer-assisted operation associated with the text content including ranking a search result, wherein the element is selected from the group of elements consisting of at least the term, the importance measure, and a sentence or paragraph containing the term. 10. The method of claim 7 , when the element is output or displayed, the display format or the function of the element includes at least a tag or a label associated with the text content, a topic term or a summary text associated with the text content, a category name or category node, or a search query.