198 resemble modern smartphones, the only differences being that tablets are relatively larger than smartphones, with screens 7 inches or larger, measured diagonally, and may not support access to a cellular network. Unlike laptops, tablets usually run mobile operating systems, alongside smartphones.
17.1.13 Offline Map Is a digital map that you can access and use even when you don’t have an active network connection. Maps has an offline feature to help you navigate safely even when your phone might be showing zero bars.
17.2 Map Elements
17.2.1 Scale
Scale refers to the relationship between the distance on the map as compared to the
distance on the ground. By using the scale, census or any other survey staff can
determine distances required for field checking, for conducting enumeration, etc. The
scale should always be shown on census/survey maps. A Scale may be expressed in
three ways:
(a)
Word statement,
(b)
Numerical fraction, and
(c)
Graphic scale. Graphic scale is commonly used in census/survey maps. A
graphic or bar scale shows the relationship between distances on the map and on the
ground by means of a bar or line, with markings to indicate distances on the ground.
17.2.2 Map Symbols Map symbols refer to figures, lines, colours, or patterns used to indicate certain features on the ground such as administrative boundaries, buildings, rivers, roads, railroads, etc. Symbols are used to show three different types of information; (a) location (b) nature or quality of the features, and (c) Quantity. Maps normally show what features are and where they are as the primary function. Maps showing how much there is of various features are primarily statistical maps.
17.2.3 Other Map Elements Refer to;
(a) Grid coordinates: describe all points on the Earth.
(b) Type of projection: indicates the amount and kind of distortion of the features.
(c) North arrow: orients the map by compass directions
(d) Date of the map: reveals how current it is.
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(e) Source of the original materials: give the idea of reliability and accuracy of the map.
(f) Sheet number: helps in locating other maps for the same area.
17.3 Codes Codes refer to uniquely identification by number of all administrative divisions of every order for which data are to be tabulated. This is made possible by the use of unique numbers assigned to them. Tanzania (Mainland and Zanzibar) has 26 regions, which are divided into districts and further subdivided into wards and villages.
17.3.1 Regional and District Codes Regional and District Codes refer to a two-digit number identifying an administrative region and district; with each respective code having two digits.
17.3.2 Ward/Shehia Code Ward/Shehia Code refers to an administrative ward or shehia. A ward/shehia code has three digits. The first two digits stand for a serial number of the ward within the district, the third digit classifies the ward/shehia into whether it is pure rural (1), pure urban (2) or mixed (3). For example, ward/shehia 031 means third ward/shehia in a district which is pure rural; 072 means seventh ward/shehia which is pure urban; and 113 means eleventh ward/shehia which is mixed, that is, part of it is rural while the rest of it is urban.
17.3.3 Village/Street Code Village/Street Code refers to a two-digit number identifying an administrative village/mtaa.
17.3.4 EA Code EA Code refers to a number identifying the smallest geographic area from which census/survey data are collected. EA code has twelve-digits which is a collection of all levels of administration including the number of and EA which has three digits. That is, an EA code comprises two-digit regional code, two-digit district code, three-digit ward/shehia code, two-digit village/street code and a three-digit EA number.
17.4 Aerial Photography It refers to a process of recording features on the earth using remote sensing instrument(s).
200 17.5 Satellite Imagery Satellite imagery refers to the collection of information through satellites, that is, information collected from an altitude of 320 kilometers (200 miles) or more. Unmanned satellites, such as Land sat 1 and 2, pass over the entire inhabited Earth many times on a regular basis, providing almost complete coverage of the Earth’s surface. The satellites use a particular sensors or scanners to sense or scan the amount of energy being reflected or radiated from a series of points into numerical values, and radio these values to receiving stations on the Earth. The values are then processed to make pictures for use in the usual interpretation.
17.6 Global Positioning System (GPS)
It refers to space-based navigation system that provides location and time information in all-
weather conditions anywhere or near the earth.
17.7 Automated Cartography
Automated cartography refers to the map production process using computers, automatic
drafting equipment, and microfilm systems. The development of automated cartography
increases the speed and accuracy while reduces the cost of map production. Automated
cartography depends on the availability of computer readable coordinates associated with
specific geographic unit. Each point on a map must be identified and recorded in machine-
readable form, producing a computer file, and once the basic file is created, it can be easily
updated.
17.8 Arc GIS This is a software that allows handling and analyzing geographic information by visualizing geographical statistics through layer building maps like climate data or trade flows. 17.8.1 ARC GIS Platform A is a computer system that analyzes and displays geographically referenced information. 17.8.2 Collector for Arc GIS Is a mobile data collection app that makes it easy to capture accurate data from the field and return it to the office. 17.8.3 ArcMap Is a geospatial software to view, edit, manage and analyze geographic data, software for creating, analyzing, and visualizing spatial data and maps. 17.8.4 Arc Catalogue Is an application that helps to create, organize, and manage all Arc GIS content. This includes various types of geographic information such as:
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• Geodatabases: These store spatial data, including feature classes, tables, and
relationships.
• Raster files: These represent imagery or gridded data.
• Map documents (MXD): These contain map layouts, symbology, and data
layers.
• Globes: These are 3D representations of the Earth’s surface.
• Layers: These define how data is displayed on maps.
• Geoprocessing models: These automate spatial analysis tasks.
• Python scripts: These allow custom scripting within ArcGIS.
• ArcGIS services: These enable sharing and publishing of data via ArcGIS
Server.
17.8.5 ArcGIS online
Is secure mapping and spatial analysis software as a service (SaaS) platform that
empowers organization to unlock geospatial insights. Built on scalable and resilient
technology, an organization can collect and manage data, analyze it, and improve
decision-making by easily sharing maps and apps. Seamlessly collaborate with the help
of a configurable sharing model and a variety of integrated apps and capabilities.
17.8.6 ArcGIS Enterprise
Is the foundational software system for GIS, powering mapping and visualization,
analytics, and data management. It is the backbone for running the Esri suite of
applications and your own custom applications.
17.9 Shapefile Is a geospatial vector data format for geographic information system (GIS) software. It is developed and regulated by Esri as a mostly open specification for data interoperability among Esri and other GIS software products. The shapefile format can spatially describe vector features: points, lines, and polygons, representing, for example, water wells, rivers, and lakes. Each item usually has attributes that describe it, such as name or temperature.
17.10 Schema Is a cognitive framework or concept that helps organize and interpret information. Simply put, a schema describes patterns of thinking and behavior that people use to interpret the world.
17.10.1 Publish a Schema Refer on how to design or take the state of the project, compare that to a database, and push those changes. Publish functionality includes the schema comparison portion, but
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then just picks up all differences and acts on them. It can also run the pre/post deploy
scripts you have set up.
17.11 Geodatabase
Is a collection of geographic datasets of various types held in a common file system folder, or
a multiuser relational database management system such as IBM Db2, Microsoft SQL
Server, Oracle, PostgreSQL, or SAP HANA.
17.12 Landmark
Is a recognizable natural or artificial feature used for navigation, a feature that stands out from
its near environment and is often visible from long distances. In modern day use, the term can
also be applied to smaller structures or features, that have become local or national symbols.
17.13 Enumeration Area Is a geographic region canvassed by one or more census representatives, commonly referred to as enumerators. These areas cover the entire territory of a given country and are composed of one or more adjacent smaller areas, often corresponding to neighbourhood blocks or other manageable units. The purpose of defining EAs is to facilitate the census enumeration process by dividing the work into smaller, more manageable sections. EAs are typically determined based on the number of households they contain, with urban areas having more households than rural areas due to the proximity of dwellings. The boundaries of an EA usually follow physical features such as roads, rivers, and fence lines, making it easier for field staff to identify their assigned area of interest. During a national census, data collection occurs at the EA level, making it the smallest statistical sample unit in the census process
17.14 EA Delineation Is the action of describing or portraying boundary precisely, the action of indicating the exact position of a border or boundary.
17.15 EA Geocode Are the specific location’s geographic coordinates, which typically include its latitude and longitude that represents a specific geographic place such as a landmark, street address, place name, or location. These coordinates help pinpoint a place on the Earth’s surface. Geocodes are plottable on maps and have applications in navigation, routing, spatial analysis, and insurance risk analytics.
17.16 Attribute Table Are database electronic storage container with a top-down structure in which the items contained are related to each other and that relationship allows for the data to be quickly and efficiently queried and retrieved for use.
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17.17 Location Is a particular place or position, an actual place or natural setting in which a film or broadcast is made, as distinct from a simulation in a studio. Is the action of locating someone or something.
17.18 Accuracy Refer to the quality or state of being correct or precise, the degree to which the result of a measurement, calculation, or specification conforms to the correct value or a standard.
204 CHAPTER EIGHTEEN SAMPLING
18.0 Introduction Sampling refers to drawing a sample or selecting a subset of elements from a population. The usual goal in sampling is to produce a representative sample. A sample is equivalent to the population on all characteristics, except that it includes fewer elements. A perfect representative sample would be a “mirror image “of the population from which it was selected, except it would include fewer elements. The selection of a sample can either be through probability or non-probability mechanism.
18.1 Population Refers to the totality of the elements under study or entire group of units, which is the focus of the study. For example, population could consist of person or non – human units such as farms, houses or establishments such as industry, schools and hospitals.
18.2 Target Population The set of elements about which information is wanted and estimates are required. Practical considerations may dictate that some units are excluded (e.g. Institutionalized individuals, the homeless, or those who are not be possible to access Without incurring excessive cost).
18.3 A Sample A set of elements taken from a population.
18.4 A Statistic A numerical characteristic of a sample.
18.5 Parameter A numerical characteristic of population.
18.6 Response rate Percentage of sampled units who actually participate in the study.
18.7 Domain of the Study Refers to a major segment of the population for which separate statistics are needed. A domain can be either a geographical area or a specified population category, such as a region or major ethnic groups. Domains are very important for the determination of a sample size and sampling distribution of statistics