`is_answered` is `true` if there is at least one positively scoring answer. It doesn't actually mean 'marked as accepted'. See more about how it works [in this answer](https://stackapps.com/a/4231/26088)

Also, 

    https://api.stackexchange.com/2.2/search/advanced?site=stackoverflow.com&page=1&pagesize=20&order=desc&sort=relevance&q=signalr

(URL without filter so I don't need key/access token)

gives the JSON:

    {  
       "items":[  
          {  
             "tags":[  
                "signalr"
             ],
             "owner":{  
                "reputation":7276,
                "user_id":960567,
                "user_type":"registered",
                "accept_rate":79,
                "profile_image":"https://www.gravatar.com/avatar/d95e231d783a218eba22a6bd04652255?s=128&d=identicon&r=PG",
                "display_name":"user960567",
                "link":"http://stackoverflow.com/users/960567/user960567"
             },
             "is_answered":true,
             "view_count":20473,
             "accepted_answer_id":7874352,
             "answer_count":3,
             "score":115,
             "last_activity_date":1439886702,
             "creation_date":1318940205,
             "question_id":7807066,
             "link":"http://stackoverflow.com/questions/7807066/how-signalr-works-internally",
             "title":"How SignalR works internally?"
          },
          {  
             "tags":[  
                "signalr"
             ],
             "owner":{  
                "reputation":7096,
                "user_id":97382,
                "user_type":"registered",
                "accept_rate":68,
                "profile_image":"https://www.gravatar.com/avatar/b154c4e4a979b7201ad47881520a08af?s=128&d=identicon&r=PG",
                "display_name":"Craig W.",
                "link":"http://stackoverflow.com/users/97382/craig-w"
             },
             "is_answered":true,
             "view_count":26263,
             "accepted_answer_id":9281143,
             "answer_count":5,
             "score":104,
             "last_activity_date":1452610249,
             "creation_date":1329236849,
             "question_id":9280484,
             "link":"http://stackoverflow.com/questions/9280484/signalr-why-choose-hub-vs-persistent-connection",
             "title":"SignalR: Why choose Hub vs. Persistent Connection?"
          },
          {  
             "tags":[  
                "c#",
                "asp.net",
                "signalr"
             ],
             "owner":{  
                "reputation":4417,
                "user_id":449907,
                "user_type":"registered",
                "accept_rate":74,
                "profile_image":"https://www.gravatar.com/avatar/b2ea20cc07619dd7cdc286f09e2ecca3?s=128&d=identicon&r=PG",
                "display_name":"Rocky Singh",
                "link":"http://stackoverflow.com/users/449907/rocky-singh"
             },
             "is_answered":true,
             "view_count":23205,
             "accepted_answer_id":8942623,
             "answer_count":14,
             "score":32,
             "last_activity_date":1456907475,
             "creation_date":1327063045,
             "question_id":8941595,
             "link":"http://stackoverflow.com/questions/8941595/signalr-signalr-hubs-giving-404-error",
             "title":"SignalR "signalr/hubs" giving 404 error"
          },
          {  
             "tags":[  
                "jquery",
                "asp.net-mvc-3",
                "signalr"
             ],
             "owner":{  
                "reputation":1872,
                "user_id":610168,
                "user_type":"registered",
                "accept_rate":56,
                "profile_image":"https://www.gravatar.com/avatar/620e1401766b11cd74f9a503fb953ed6?s=128&d=identicon&r=PG",
                "display_name":"bdparrish",
                "link":"http://stackoverflow.com/users/610168/bdparrish"
             },
             "is_answered":true,
             "view_count":8259,
             "answer_count":5,
             "score":13,
             "last_activity_date":1349459751,
             "creation_date":1326942995,
             "question_id":8920621,
             "link":"http://stackoverflow.com/questions/8920621/signalr-startup",
             "title":"SignalR - StartUp"
          },
          {  
             "tags":[  
                "signalr"
             ],
             "owner":{  
                "reputation":162,
                "user_id":1447975,
                "user_type":"registered",
                "accept_rate":50,
                "profile_image":"https://www.gravatar.com/avatar/7ecb2a888caf6ef8b5fbdce03d725f92?s=128&d=identicon&r=PG",
                "display_name":"CBaker",
                "link":"http://stackoverflow.com/users/1447975/cbaker"
             },
             "is_answered":true,
             "view_count":40,
             "accepted_answer_id":35758152,
             "answer_count":1,
             "score":0,
             "last_activity_date":1457012195,
             "creation_date":1456952929,
             "question_id":35758082,
             "link":"http://stackoverflow.com/questions/35758082/signalr-the-signalr-hubs-file",
             "title":"SignalR - The signalr/hubs file"
          },
          {  
             "tags":[  
                "requirejs",
                "signalr"
             ],
             "owner":{  
                "reputation":38,
                "user_id":327911,
                "user_type":"registered",
                "profile_image":"https://www.gravatar.com/avatar/4063cd31f7de485431927b28f82828c0?s=128&d=identicon&r=PG",
                "display_name":"coreyperkins",
                "link":"http://stackoverflow.com/users/327911/coreyperkins"
             },
             "is_answered":true,
             "view_count":2833,
             "accepted_answer_id":11479051,
             "answer_count":2,
             "score":5,
             "last_activity_date":1405005809,
             "creation_date":1342216920,
             "last_edit_date":1342323312,
             "question_id":11478946,
             "link":"http://stackoverflow.com/questions/11478946/require-js-signalr",
             "title":"Require.js + SignalR"
          },
          {  
             "tags":[  
                "asp.net",
                "signalr"
             ],
             "owner":{  
                "reputation":44,
                "user_id":1847005,
                "user_type":"registered",
                "profile_image":"https://www.gravatar.com/avatar/13a791640ad72effea4ed5e545ad8a61?s=128&d=identicon&r=PG",
                "display_name":"whebz",
                "link":"http://stackoverflow.com/users/1847005/whebz"
             },
             "is_answered":true,
             "view_count":393,
             "accepted_answer_id":14099327,
             "answer_count":2,
             "score":5,
             "last_activity_date":1356942551,
             "creation_date":1356010717,
             "last_edit_date":1356014159,
             "question_id":13973425,
             "link":"http://stackoverflow.com/questions/13973425/signalr-methodaccessexception",
             "title":"SignalR MethodAccessException"
          },
          {  
             "tags":[  
                "c#",
                "signalr"
             ],
             "owner":{  
                "reputation":83,
                "user_id":2151460,
                "user_type":"registered",
                "profile_image":"https://www.gravatar.com/avatar/594ab11fd7c482dbdc5c7d854de4fff0?s=128&d=identicon&r=PG",
                "display_name":"Dexception",
                "link":"http://stackoverflow.com/users/2151460/dexception"
             },
             "is_answered":false,
             "view_count":198,
             "answer_count":0,
             "score":1,
             "last_activity_date":1436399925,
             "creation_date":1436399925,
             "question_id":31305882,
             "link":"http://stackoverflow.com/questions/31305882/signalr-err-conection-refused-on-signalr-hubs",
             "title":"SignalR ERR_CONECTION_REFUSED on signalr/hubs"
          },
          {  
             "tags":[  
                "signalr"
             ],
             "owner":{  
                "reputation":10345,
                "user_id":166303,
                "user_type":"registered",
                "accept_rate":75,
                "profile_image":"https://i.sstatic.net/29eUl.jpg?s=128&g=1",
                "display_name":"reach4thelasers",
                "link":"http://stackoverflow.com/users/166303/reach4thelasers"
             },
             "is_answered":true,
             "view_count":5296,
             "accepted_answer_id":9995081,
             "answer_count":3,
             "score":24,
             "last_activity_date":1372554893,
             "creation_date":1333447281,
             "question_id":9991035,
             "link":"http://stackoverflow.com/questions/9991035/securing-signalr-calls",
             "title":"Securing SignalR Calls"
          },
          {  
             "tags":[  
                "timer",
                "signalr"
             ],
             "owner":{  
                "reputation":1783,
                "user_id":645924,
                "user_type":"registered",
                "accept_rate":78,
                "profile_image":"https://www.gravatar.com/avatar/2bcc518c6f92a560dc32647190319ace?s=128&d=identicon&r=PG",
                "display_name":"Ryan",
                "link":"http://stackoverflow.com/users/645924/ryan"
             },
             "is_answered":true,
             "view_count":481,
             "answer_count":1,
             "score":1,
             "last_activity_date":1342565236,
             "creation_date":1342002034,
             "question_id":11430517,
             "link":"http://stackoverflow.com/questions/11430517/signalr-overhead",
             "title":"signalR overhead"
          },
          {  
             "tags":[  
                "c#",
                "asp.net",
                "asp.net-mvc",
                "signalr"
             ],
             "owner":{  
                "reputation":8,
                "user_id":899974,
                "user_type":"registered",
                "profile_image":"https://www.gravatar.com/avatar/77be3b28cd3567ffa632d75aba0a2090?s=128&d=identicon&r=PG",
                "display_name":"ishahrier",
                "link":"http://stackoverflow.com/users/899974/ishahrier"
             },
             "is_answered":false,
             "view_count":397,
             "answer_count":0,
             "score":1,
             "last_activity_date":1414669608,
             "creation_date":1404240425,
             "last_edit_date":1414669608,
             "question_id":24517253,
             "link":"http://stackoverflow.com/questions/24517253/signalr-authentication",
             "title":"SignalR authentication"
          },
          {  
             "tags":[  
                "javascript",
                "signalr",
                "signalr-hub"
             ],
             "owner":{  
                "reputation":10,
                "user_id":1576800,
                "user_type":"registered",
                "accept_rate":50,
                "profile_image":"https://www.gravatar.com/avatar/d60ba6a7b217f636f7bcace4ed116446?s=128&d=identicon&r=PG",
                "display_name":"Stuart Armstrong",
                "link":"http://stackoverflow.com/users/1576800/stuart-armstrong"
             },
             "is_answered":false,
             "view_count":625,
             "answer_count":1,
             "score":1,
             "last_activity_date":1345537730,
             "creation_date":1344131433,
             "last_edit_date":1344132031,
             "question_id":11813373,
             "link":"http://stackoverflow.com/questions/11813373/signalr-undefined",
             "title":"signalR undefined"
          },
          {  
             "tags":[  
                "signalr",
                "high-load"
             ],
             "owner":{  
                "reputation":105,
                "user_id":3106031,
                "user_type":"registered",
                "accept_rate":50,
                "profile_image":"https://www.gravatar.com/avatar/70134c59b75fae8967d97bb2769ce85b?s=128&d=identicon&r=PG",
                "display_name":"Viet NT",
                "link":"http://stackoverflow.com/users/3106031/viet-nt"
             },
             "is_answered":true,
             "view_count":2040,
             "answer_count":1,
             "score":3,
             "last_activity_date":1407327358,
             "creation_date":1407326548,
             "question_id":25159905,
             "link":"http://stackoverflow.com/questions/25159905/signalr-performance",
             "title":"SignalR performance"
          },
          {  
             "tags":[  
                "c#",
                "asp.net-mvc",
                "signalr"
             ],
             "owner":{  
                "reputation":8637,
                "user_id":1477388,
                "user_type":"registered",
                "accept_rate":91,
                "profile_image":"https://www.gravatar.com/avatar/260bb71d267800168d25e7c3be88b1c5?s=128&d=identicon&r=PG",
                "display_name":"user1477388",
                "link":"http://stackoverflow.com/users/1477388/user1477388"
             },
             "is_answered":true,
             "view_count":1270,
             "accepted_answer_id":22918490,
             "answer_count":1,
             "score":7,
             "last_activity_date":1396889530,
             "creation_date":1396887314,
             "question_id":22917723,
             "link":"http://stackoverflow.com/questions/22917723/signalr-security",
             "title":"SignalR Security"
          },
          {  
             "tags":[  
                "signalr",
                "signalr-hub"
             ],
             "owner":{  
                "reputation":3951,
                "user_id":17194,
                "user_type":"registered",
                "accept_rate":90,
                "profile_image":"https://www.gravatar.com/avatar/b0e76ddb571766c264d3a4bdff71c27f?s=128&d=identicon&r=PG",
                "display_name":"ChrisCa",
                "link":"http://stackoverflow.com/users/17194/chrisca"
             },
             "is_answered":true,
             "view_count":1376,
             "accepted_answer_id":11950505,
             "answer_count":2,
             "score":2,
             "last_activity_date":1344940607,
             "creation_date":1344502812,
             "last_edit_date":1344512940,
             "question_id":11879927,
             "link":"http://stackoverflow.com/questions/11879927/signalr-disconections",
             "title":"SignalR Disconections"
          },
          {  
             "tags":[  
                "c#",
                "asp.net",
                "node.js",
                "signalr"
             ],
             "owner":{  
                "reputation":885,
                "user_id":3676005,
                "user_type":"registered",
                "accept_rate":96,
                "profile_image":"https://i.sstatic.net/viEMs.png?s=128&g=1",
                "display_name":"acostela",
                "link":"http://stackoverflow.com/users/3676005/acostela"
             },
             "is_answered":false,
             "view_count":84,
             "answer_count":0,
             "score":0,
             "last_activity_date":1450100534,
             "creation_date":1450100534,
             "question_id":34268530,
             "link":"http://stackoverflow.com/questions/34268530/signalr-nodejs",
             "title":"SignalR + nodeJS"
          },
          {  
             "tags":[  
                "c#",
                "json",
                "json.net",
                "signalr",
                ".net-4.5"
             ],
             "owner":{  
                "reputation":15149,
                "user_id":144746,
                "user_type":"registered",
                "accept_rate":95,
                "profile_image":"https://www.gravatar.com/avatar/170e317e1e3d42b520786bcec9dfb409?s=128&d=identicon&r=PG",
                "display_name":"Voo",
                "link":"http://stackoverflow.com/users/144746/voo"
             },
             "is_answered":true,
             "view_count":287,
             "accepted_answer_id":32404249,
             "answer_count":1,
             "score":5,
             "last_activity_date":1441670352,
             "creation_date":1441034515,
             "last_edit_date":1441094888,
             "question_id":32314638,
             "link":"http://stackoverflow.com/questions/32314638/signalr-typenamehandling",
             "title":"SignalR Typenamehandling"
          },
          {  
             "tags":[  
                "asp.net",
                "iis",
                "signalr"
             ],
             "owner":{  
                "reputation":543,
                "user_id":685590,
                "user_type":"registered",
                "accept_rate":86,
                "profile_image":"https://www.gravatar.com/avatar/8bfc28769485f5a754c4415ae146d7b3?s=128&d=identicon&r=PG",
                "display_name":"user685590",
                "link":"http://stackoverflow.com/users/685590/user685590"
             },
             "is_answered":true,
             "view_count":14257,
             "accepted_answer_id":11187447,
             "answer_count":8,
             "score":24,
             "last_activity_date":1431685061,
             "creation_date":1340363423,
             "last_edit_date":1370488030,
             "question_id":11155064,
             "link":"http://stackoverflow.com/questions/11155064/signalr-signalr-hubs-404-not-found",
             "title":"SignalR /signalr/hubs 404 Not Found"
          },
          {  
             "tags":[  
                "javascript",
                "asp.net",
                "angularjs",
                "signalr"
             ],
             "owner":{  
                "reputation":36,
                "user_id":5731750,
                "user_type":"registered",
                "profile_image":"https://www.gravatar.com/avatar/f9854c745e4162a7e093362fcdeebb73?s=128&d=identicon&r=PG&f=1",
                "display_name":"wroe12",
                "link":"http://stackoverflow.com/users/5731750/wroe12"
             },
             "is_answered":false,
             "view_count":33,
             "answer_count":0,
             "score":0,
             "last_activity_date":1455992331,
             "creation_date":1455992331,
             "question_id":35527177,
             "link":"http://stackoverflow.com/questions/35527177/signalr-asp-net",
             "title":"SignalR ASP.NET"
          },
          {  
             "tags":[  
                "c#",
                "signalr",
                "amazon-elasticache"
             ],
             "owner":{  
                "reputation":972,
                "user_id":636160,
                "user_type":"registered",
                "accept_rate":23,
                "profile_image":"https://i.sstatic.net/KR6nl.jpg?s=128&g=1",
                "display_name":"Andy",
                "link":"http://stackoverflow.com/users/636160/andy"
             },
             "is_answered":true,
             "view_count":737,
             "answer_count":1,
             "score":47,
             "last_activity_date":1456237640,
             "creation_date":1435254722,
             "last_edit_date":1448438993,
             "question_id":31057333,
             "link":"http://stackoverflow.com/questions/31057333/using-signalr-with-elasticache-fails",
             "title":"Using SignalR with ElastiCache fails"
          }
       ],
       "has_more":true,
       "quota_max":300,
       "quota_remaining":234
    }

which *does* contain the screenshotted question:

    {  
         "tags":[  
            "c#",
            "asp.net",
            "asp.net-mvc",
            "signalr"
         ],
         "owner":{  
            "reputation":8,
            "user_id":899974,
            "user_type":"registered",
            "profile_image":"https://www.gravatar.com/avatar/77be3b28cd3567ffa632d75aba0a2090?s=128&d=identicon&r=PG",
            "display_name":"ishahrier",
            "link":"http://stackoverflow.com/users/899974/ishahrier"
         },
         "is_answered":false,
         "view_count":397,
         "answer_count":0,
         "score":1,
         "last_activity_date":1414669608,
         "creation_date":1404240425,
         "last_edit_date":1414669608,
         "question_id":24517253,
         "link":"http://stackoverflow.com/questions/24517253/signalr-authentication",
         "title":"SignalR authentication"
      },