{"id":79911,"date":"2017-10-10T09:50:36","date_gmt":"2017-10-10T09:50:36","guid":{"rendered":"http:\/\/www.esri.com\/arcgis-blog\/products\/product\/uncategorized\/geocoding-delivering-high-location-accuracy\/"},"modified":"2018-03-26T21:14:59","modified_gmt":"2018-03-26T21:14:59","slug":"geocoding-delivering-high-location-accuracy","status":"publish","type":"blog","link":"https:\/\/www.esri.com\/arcgis-blog\/products\/analytics\/analytics\/geocoding-delivering-high-location-accuracy","title":{"rendered":"Geocoding: Delivering High Location Accuracy"},"author":7131,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"open","ping_status":"closed","template":"","format":"standard","meta":{"_acf_changed":false,"_searchwp_excluded":""},"categories":[23341,23261,22851,22941,24371,22871,25841,23351],"tags":[34721,33881,23551,22901,24391,37081,23391,29961,23401,33901],"industry":[],"product":[36571,36551,36561],"class_list":["post-79911","blog","type-blog","status-publish","format-standard","hentry","category-analytics","category-field-mobility","category-national-government","category-mapping","category-public-safety","category-state-government","category-telecommunications","category-transportation","tag-accuracy","tag-batch-geocoding","tag-location-analytics","tag-national-government","tag-public-safety","tag-risk-assessment","tag-spatial-analytics","tag-telecom","tag-transportation","tag-world-geocoding","product-arcgis-enterprise","product-arcgis-online","product-arcgis-pro"],"acf":{"short_description":"Geocoding is a fundamental GIS process for plotting your data on the map. It is often the first step in applying GIS to understand the wh...","flexible_content":[{"acf_fc_layout":"content","content":"

Geocoding is a fundamental GIS process for plotting your data on the map. It is often the first step in applying GIS to understand the where<\/em>. The accuracy of plotted points directly correlates with the success of downstream decisions. Regardless of the GIS application you choose, you will make decisions based on analysis and this analysis must be accurately geocoded.<\/p>\n

To ensure geocoding accuracy, consider these five questions:<\/p>\n

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  1. How do you define accuracy<\/strong> and why does it matter?<\/li>\n
  2. What are the benefits of using a solution built with authoritative,<\/strong> commercial street data<\/strong> versus <\/strong>a low-cost or free solution that uses OpenStreetMap and Census TIGER data<\/strong>?<\/li>\n
  3. Which match levels are supported by my current geocoding solution, and what is the benefit of cascading<\/strong> to get the best match at the highest accuracy?<\/li>\n
  4. What is the difference between a Address point, Delivery point, and an Address Range<\/strong> match?<\/li>\n
  5. What does the status \u2018Match, Tie, or Unmatch\u2019<\/strong> mean and what does the score<\/strong> indicate?<\/li>\n<\/ol>\n

    Defining Accuracy<\/strong><\/p>\n

    Many people get confused when describing Accuracy<\/em> and Precision<\/em>. Sometimes these terms are incorrectly thought to be interchangeable.<\/p>\n

    Here are the correct definitions. Accuracy is used to describe the closeness of a measurement to a true value. Precision is the closeness of agreement among a set of results. In the graphic below, you can see the differences between each.<\/p>\n

    \"\"<\/a>
    This diagram shows the difference between Accuracy and Precision. Geocoding matches can be highly precise and highly accurate as well as inaccurate and imprecise, and anywhere in between.\u00a0 Image Credit: http:\/\/www.antarcticglaciers.org\/<\/figcaption><\/figure>\n

    In geocoding, you can obtain highly accurate, highly precise results or results with low accuracy and precision, or anywhere along the spectrum depending on your solution. Accurate and precise geocoding results are essential for many use cases as discussed in our previous blog<\/a>. \u00a0They greatly affect the decisions that stakeholders make with analysis downstream. Many factors influence accuracy and precision, as we will discuss.<\/p>\n

    Street Reference Datasets and Accuracy<\/strong><\/p>\n

    To be able to match a spatial coordinate to your address record, you need a street reference dataset that contains the address and the associated coordinates. This will be used by the software as a reference<\/em> to match your input address to a coordinate. There are three street reference data options:<\/p>\n