turning to the drawings , wherein like reference numerals refer to like elements , the invention is illustrated as being implemented in a suitable environment . the following description is based on embodiments of the invention and should not be taken as limiting the invention with regard to alternative embodiments that are not explicitly described herein . aspects of the present invention may be practiced in the representative communications environment 100 of fig1 . connected together via any or all of various known networking technologies 102 are media content providers ( e . g ., cable television head - end servers and the like ) and other servers such as media analyzers 104 , advertisement brokers 106 , and recommender systems 108 . ( the functions of these servers are discussed below .) for ease of illustration , only one of each type of server 104 , 106 , 108 is shown , but multiples of each can exist and can work together , as discussed below . the servers 104 , 106 , 108 provide , via the networking technologies 102 , sentiment analysis of media content and related services to end - user devices . traditional end - user devices are supported by “ wireline ” network technologies ( e . g ., fiber , wire , and cable ) 112 . for example , a set - top box 114 generally receives television programming from various media content providers and provides a user interface ( e . g ., an interactive program guide ) for selecting and viewing content from the cable provider . a digital video recorder ( not shown ) can store programming for later viewing . video content may be viewed on a television monitor 116 . in some situations , a laptop computer 118 can access both television content and web - based services either wirelessly or via the wireline network 112 . a home gateway , kiosk , digital sign , or media - restreaming device ( not shown ) are other possible end - user devices . ( a media - restreaming device transfers content between disparate types of networks . for example , it receives content from a cable television system 112 and then transmits that content over a local radio link such as wifi to the cellular telephone 110 . the media - restreaming device usually operates in both directions to carry messages between the networks . in some embodiments , aspects of the present invention are practiced by a media - restreaming device .) television programming can also be delivered to non - traditional subscriber devices such as the cellular telephone 110 . this telephone 110 communicates wirelessly to a wireless base station ( not shown but known in the art ) to access the public switched telephone network , the internet , or other networks to access web - based services as well as the television - delivery services provided by the media content providers . wireless and wireline network technologies generally support two - way traffic : media content and related information are delivered to the end - user devices 110 , 114 , 116 , 118 , and requests go “ up ” to the servers 104 , 106 , 108 . a typical user may split his attention by interacting with any or all of the end - user devices 110 , 114 , 116 , 118 at roughly the same time or in a temporally overlapping manner . examples in the present discussion usually assume that the user is watching the television monitor 116 and possibly interacting with it through the set - top box 114 . in some situations , the user at least occasionally gives some of his attention to a “ companion device ” such as the cellular telephone 110 . to illustrate aspects of the present invention , consider a user watching a television program on the television monitor 116 . a media analysis application analyzes the television program ( possibly before the program is delivered to the user or possibly in real time ) for sentiments . the media analysis application produces a sentiment map of the television program . the map lists segments of the program along with sentiments ( e . g ., “ happy ,” “ exciting ,” unknown ) associated with the segments . ( for the sake of simplicity , the present discussion assumes that the media analysis application is fully embodied on one device , but in other embodiments this application can reside at least partially within the head - end of a cable provider , on a web server 104 , on an end - user device such as the cellular telephone 110 or set - top box 114 , or on some combination of these .) in some embodiments , the sentiment map is then made available to services such as an advertisement broker 106 . by reviewing the sentiment map , the advertisement broker 106 , determines , for example , that the next 30 seconds of the television program are “ exciting .” the advertisement broker 106 finds an advertisement whose sponsor wishes the advertisement to be associated with “ exciting ” content . the advertisement broker 106 then places a bid to place that advertisement either on the television monitor 116 or on the user &# 39 ; s companion device 110 . if the bid is accepted , then the advertisement is placed temporally near the exciting segment of the television program , to the satisfaction of the advertisement sponsor . ( in some situations , the advertisement is delivered to the set - top box 114 , and the set - top box 114 delivers the advertisement to the television monitor 116 . these sorts of connection options are well known in the art and need not be further discussed .) particular aspects of the media analysis application are discussed below in conjunction with fig3 . two examples of applications that use the sentiment map are discussed below in conjunction with fig4 and 5 . fig2 shows the major components of a representative server 104 , 106 , 108 or end - user device 110 , 114 , 118 . network interfaces ( also called transceivers ) 200 send and receive media presentations and messages such as the sentiment map . a processor 202 controls the operations of the device and , in particular , supports aspects of the present invention as illustrated in fig3 through 5 , discussed below . the user interface 204 supports a user &# 39 ; s ( or administrator &# 39 ; s ) interactions with the device . specific uses of these components by specific devices are discussed as appropriate below . fig3 presents a method for creating a sentiment map . the method begins in step 300 when the media analyzer application receives a media content item . first note that “ media content item ” is meant very broadly : it can be a television program or movie , but it could also be a sound - only clip , a message of any kind ( e . g ., an e - mail with attached or embedded content ), a telephone call with or without accompanying video , or even an advertisement or an interactive computer game . for simplicity &# 39 ; s sake , the following discussion often assumes that the media content item is a television program presented on the television monitor 116 , but all these other possibilities should be kept in mind . “ receiving ” encompasses many possibilities . if the media analyzer is embodied on a network server 104 , then it can download the full content item and process it according to the remaining steps in fig3 . this “ offline ” method has several advantages . first , the media analyzer 104 can take whatever time it needs to perform the analysis . second , because the media analyzer 104 can review the entire content item , it can better estimate the beginning and end of a particular segment . ( see the detailed description of delimitation that accompanies step 304 below .) third , a network server 104 can perform the sentiment analysis once for a given content item and then provide the map as needed , rather than having each recipient of the content item perform its own analysis . most of these advantages also apply if the analysis is done offline by a local user device , e . g ., by the user &# 39 ; s laptop computer 118 analyzing a content item stored on the user &# 39 ; s digital video recorder . there are cases , however , where offline processing is simply not an option . this is especially true when the media analyzer cannot acquire access to the full media content item significantly before the sentiment map is required . the content item may be a live event streamed to a user &# 39 ; s television monitor 116 . even if the content item is not actually a live broadcast , if it is being shown for the first time ( e . g ., the newest episode of a television series ), then it is unlikely that the media analyzer will be allowed access to all of the content item before it is sent to users . in these situations , the media analyzer attempts to create the sentiment map in “ real time ,” that is , while the content item is being received . in terms of fig3 , this means that steps 300 through 308 ( and possibly even steps 310 and 312 ) are performed , in some sense , concurrently rather than consecutively . in one embodiment , the media analyzer application runs on the user &# 39 ; s set - top box 114 , and it analyzes the programming as it is being received from the cable system 112 and then sent to the television monitor 116 . in some embodiments , the programming can be buffered and delayed for a few seconds by the set - top box 114 to allow the media analysis to “ keep ahead ” of the point in the content item currently being viewed . the next two steps , 302 and 304 , are , in most embodiments , inseparable . the present discussion attempts , as far as possible , to present these two steps independently , but it should be kept in mind that the detailed discussion of each step informs that of the other . in step 302 , the media content item is analyzed for sentiments . ideally , every point in time of the content item is associated with one or more sentiment - state keywords that express the mood of the content item at that point in time . ( see also the discussion of step 306 below .) step 304 is a recognition that , generally , the “ point in time ” is actually a relatively short temporal segment of the content item . for example , the segment from 20 seconds into the content item to 30 seconds is considered to be “ happy ,” and the segment from 53 seconds to 1 minute , 20 seconds is “ exciting .” clearly , the sentiments associated with a segment and the delimitation of the segment are interrelated . in fact , it is usually the sentiment analysis itself that determines the delimitation of the segments . that is , when the sentiment “ happy ” is found at one time , the surrounding time in the content item can be analyzed to determine the approximate temporal extent of this happiness . that temporal extent then defines the limits of the segment that is associated with happiness . sometimes , metadata are available with the content item that help in delimiting the segments ( e . g ., a scene list with start and stop times ). focusing again on step 302 , many inputs may be used by the media analyzer application . soundtracks generally provide distinct cues to viewers to know what sentiment is expected ( e . g ., a low , slow cadence in a minor key is usually associated with sorrow or loss by human hearers ), and well known tools are available to the media analyzer to extract this information . the words being said , and how they are said , also often contain clear sentiment cues . similarly , the video itself may contain cues , such as the amount of time between cuts ( exciting scenes usually cut very often ), light levels , the amount of shadowing of a speaker &# 39 ; s face , and how the main characters are placed with respect to one another . in some situations , the media analysis application can use metadata associated with the media content item such as close - captioning information , an electronic program guide listing , or a script with staging instructions . a sophisticated media analysis application can mine further sources of information . one intriguing possibility considers “ social - networking ” metadata , that is , online posts and commentary produced by viewers of the media content item . these comments are often produced while the content item is being viewed . other comments are posted later . all of these comments can be reviewed in an attempt to refine the sentiment analysis . consider a case where the analysis application reviews the video and audio of a segment and , based on that review , associates an “ exciting ” keyword with that segment . however , a scan of online posts reveals a surprising number of viewers who found this same segment to be poorly conceived and woodenly acted . these viewers were disappointed and bored with the segment . the analysis application can take these reviews into account by downgrading a confidence value ( see the discussion of step 306 below ) associated with the “ exciting ” keyword or even by assigning both an “ exciting ” keyword and a “ boring ” keyword to the same segment , the former indicating the director &# 39 ; s intent , and the latter indicating the result actually achieved . some embodiments use further sources of information during the evaluation . the media analysis application can attempt to map a particular user &# 39 ; s expected response to segments of the media content item . ( this is very specific as compared to the above discussion of online posts , where the posts reflect the responses of the general population to a segment .) here , the information specific to a particular user can include , for example , a preference profile of the user , purchasing and other behavioral information , demographic information , and even current situational information such as the presence of friends and family during the viewing of the content item . all of this information can be considered when making a sentiment map personalized to this user . in the example mentioned in the summary , the personalized sentiment map may tag a segment as “ exciting ” because this particular user is known to be an enthusiast for dog shows . the same segment may not be not tagged as exciting in a non - personalized sentiment map if the general public does not share this enthusiasm . moving now to step 304 , in some situations the entire media content item is made up of only one segment . if , for example , the content item is very short , such as a 30 - second advertisement , then it may present only one sentiment state throughout . generally , however , several segments can be defined within one content item . the segments may even overlap as , for example , when , partway through a “ happy ” segment , an “ exciting ” segment begins . the delimitation produced by the media analysis application is often imprecise . to address this possibility , sophisticated embodiments attach to each delimitation a confidence value . for example : “ it is 90 % probable that this happy segment lasts for at least the next 20 seconds , and 65 % probable that it continues for a further 15 seconds after that .” it should be noted that , in many situations , the delimited segments do not encompass the entire content item . some portions of the content item may simply not express a sentiment , or the media analysis application cannot discover the particular sentiment intended . in step 306 , one or more sentiment - state keywords are associated with delimited segments . any types of keywords can be used here including , for example , “ happy ,” “ sad ,” “ exciting ,” “ boring ,” “ funny ,” “ romantic ,” “ violent ,” “ successful ,” and the like . ( as noted just above , the media analysis application may not be able to associate any sentiment - state keyword with a particular segment . in some embodiments , the keyword “ unknown ” is then used .) as the tools available to the media analysis application improve , it is expected that the list of keywords will increase . some applications that use the sentiment map ( see in particular the discussion accompanying fig4 and 5 below ) are interested in knowing not only the sentiments associated with a segment , but the amplitudes of those sentiments , that is , not only “ this segment is funny ,” but also “ this segment is very , very funny ” or “ this is the funniest segment in the entire media content item .” the sentiment map can include confidence values for each associated sentiment keyword and the amplitude ( if any ) of the keywords . step 308 stores the information generated by the evaluation and delimitation in a sentiment map . any number of types of data representation are possible here . it should be noted that overall , the map is very much smaller than the media content item itself . the map can be sent to applications that need it ( step 310 ). ( see the discussion of example applications accompanying fig4 and 5 below .) if the map is needed in real time , then parts of it can be sent out to waiting applications as they become available ( e . g ., segment by segment ). in optional step 312 , the sentiment mapping of a segment is revised based on further information , presumably information that was not available when the original sentiment map was created for the segment . the online social - network posts , mentioned above in relation to step 302 , are especially relevant here . because some applications may need to use the sentiment map in real time ( fig4 gives an example ), the media analyzer produces an initial sentiment map as quickly as it can with whatever information is at hand . some online comments may be posted too late to be considered for this real - time analysis , but they can be used in the re - evaluation of step 312 . portions of the media content item itself may also count as “ further information ” for the purposes of step 312 . as mentioned above in the discussion of offline vs . real - time processing in relation to step 300 , offline processing has the advantage that it can view the entire media content item when deciding how to delimit each segment . a real - time media analyzer does not have that option , but , after receiving more or even all of the content item , it can achieve much of the results of offline processing by re - considering the delimitation of segments as a result of the re - evaluation of step 312 . many types of applications can make use of the sentiment map . for example , the producer or provider of the media content item can review the map ( especially when online posts are considered when making the map ) to compare the director &# 39 ; s intent with the actual effect achieved by the content item . fig4 and 5 present two other possibilities . fig4 presents a method whereby an advertisement broker 106 uses the sentiment map when deciding where to place advertisements . the method begins in step 400 when the advertisement broker 106 receives the sentiment map . as discussed above , this may be a map of the entire media content item , produced offline by , say , a media analysis server 104 . also of interest is the case where the advertisement broker 106 receives the map segment by segment as produced in real time , as , for example , the content item is being distributed to viewers via the cable television system 112 . in any case , the advertisement broker 106 in step 402 compares the sentiment keywords and delimitation of a segment with a candidate advertisement . for example , the sponsor of this particular advertisement may have told the advertisement broker 106 that this advertisement should be shown in conjunction with “ exciting ” segments of the media content item . in another case , the sponsor did not so inform the advertisement broker 106 of its intent . instead , a sentiment map is created for the advertisement itself ( as noted above in relation to step 304 , this map may only contain a single segment ). that is , it is recognized that an advertisement is also a media content item in its own right and can be subjected to the same type of analysis described above in reference to fig3 . in this case , the analysis may show that the advertisement is both “ exciting ” and “ upbeat .” the advertisement broker 106 can then infer that this advertisement would be best received if it were shown during “ exciting ” or “ upbeat ” segments of the media content item that the user is watching on his television monitor 116 . regardless of how the advertisement broker 106 determines which sentiments are most favorable to this advertisement , the advertisement is compared against the sentiment map . the comparison may also consider the amplitude of the sentiment and the delimitation of the segment ( i . e ., the segment may be too short to use with this advertisement ). confidence values in the map can also be considered : if the content item is drawing to a close , and if the advertisement broker 106 is tasked with presenting a given number of advertisements during the presentation of the content item , then the advertisement broker 106 may have to settle for a less than ideal , or for a less confidently ideal , segment for the advertisement . if a match is favorable enough ( usually as defined by the advertisement sponsor or as inferred by the advertisement broker 106 ), then the advertisement broker 106 proceeds to step 404 a where it attempts to place this advertisement in conjunction with this segment several implementations are possible for “ attempting to place ” the advertisement . in the example of step 404 b , the advertisement broker 106 submits a bid to place the advertisement at a given time . the bid can include a proposed fee to be paid to the content provider , and can specify whether the advertisement is to be placed within the stream of the media content item itself ( as viewed on the television monitor 116 to continue the pervasive example of this discussion ) or on a companion device , such as the user &# 39 ; s cellular telephone 110 . of course , if the latter is desired , then well known methods can be applied to determine whether or not the user has a companion device , whether or not that device is turned on , and whether or not the user is interacting with that device ( indicating that the companion device has captured at least some of the user &# 39 ; s attention ). if the bid is accepted , then the advertisement is placed accordingly . in step 312 of fig3 , the sentiment map is redrawn as more information becomes available to the media analysis application . in optional step 406 of fig4 , the advertisement broker 106 reviews the revised map . if a bid was placed and accepted , but the revised map shows that the segment was not all it was thought to be ( e . g ., based on viewer &# 39 ; s online responses , a supposedly “ romantic ” scene fell flat ), then the advertisement broker 106 can request a refund of part of the bid price . the possibility of a refund could make advertisement brokers 106 more willing to place a reasonable amount of reliance on sentiment mapping and on placing bids based on these maps . fig5 presents a recommender system 108 that uses sentiment maps . in steps 500 and 502 , the recommender 108 receives sentiment maps of two media content items . the maps are compared in step 504 , and , if the comparison is favorable in some sense , then the two content items are associated with one another in step 506 . ( this is a generalization of the special case discussed above in relation to step 402 of fig4 where a sentiment map of an advertisement is compared against the map of a content item to see where the advertisement should be placed .) generally , this means that the two content items have similar sentiment maps . for example , two classic “ tear jerkers ,” though very different in plot and staging , may exhibit a similar progression of sentiments . ( this is one reason , in fact , that such movies are called “ formulaic :” the formula generally refers to the sentiments evoked scene by scene in addition to , or instead of , the plot elements .) thus sentiment maps can be used to categorize content items in a more meaningful fashion than categorization by actors , setting , or plot elements . if a user is known to like one content item , then a second content item with a similar sentiment map can be recommended to him in step 508 . the user &# 39 ; s reaction to the recommendation may help to improve the quality of the sentiment mapping . in view of the many possible embodiments to which the principles of the present invention may be applied , it should be recognized that the embodiments described herein with respect to the drawing figures are meant to be illustrative only and should not be taken as limiting the scope of the invention . for example , many other sentiment keywords are possible , and other applications of sentiment mapping can be considered . therefore , the invention as described herein contemplates all such embodiments as may come within the scope of the following claims and equivalents thereof .