TEORÍA GENERAL DE SISTEMAS

In the State of South Carolina, the eighth grade social studies curriculum consists of the study of the state. Social Studies skills are taught and reinforced to aid in the student’s comprehension of the important role South Carolina plays in the history of the United States. This course is PASS-tested (South Carolina state assessment) and is based on South Carolina social studies standards, making this grade appropriate for the SC MAPS program. Google Earth was selected over other free digital globes available due to its familiarity and popularity among the general public. In this section, the two curriculum components utilized in the study as instructional media, SC MAPS and Google Earth, are described.

About SC MAPS

South Carolina Maps and Aerial Photographic Systems (SC MAPS) is a standards-based interdisciplinary middle school curriculum utilizing a diverse collection of aerial photographic and satellite images, maps, transparencies, and topographic maps. Originally designed in 1989, the curriculum has been updated several times to its most recent 4th _{edition in 2004 by its authors Dr. Peggy W. Cain of the South Carolina}

Department of Education, Dr. John R. Wagner of the Department of Geological Sciences at Clemson University, and James B. Berry, III of the South Carolina Department of Natural Resources. This curriculum was funded by the ESEA, Title II Dwight D. Eisenhower Mathematics and Science Education Act, South Carolina Commission on Higher Education Cooperative Demonstration Grant Program, Harry Hampton Memorial Wildlife Fund, Duke Power Company Foundation, South Carolina University Research and Education Foundation, and the National Science Foundation.

The map products for this curriculum were carefully chosen to provide different spatial perspectives in a variety of map scales. The SC MAPS curriculum was designed to make connections between:

 Geologic events that have produced the state's five landform regions;

 Drainage systems, wetlands, and landform regions that have had an impact on the

state's historical events, cultural diversity, and important wildlife habitats;

 Economic trends and regional differences that have resulted in land use diversity in

relation to the state's industries, agriculture, and tourism;

 Historical events, regional customs, stories, and folk tales that have reflected the state's cultural diversity;

 Mathematical applications that have been used to solve problems involving concepts

of fractions, decimals, percentages; principles of organizing data, graphic representation of numerical facts, and estimation.

The maps are utilized as a teaching tool by which students are given an

opportunity to relate basic landform regions, historical development, and current land use patterns. Infrared photographs and topographic maps from the National High Altitude Photography Program (NHAP) and the United States Geological Survey (USGS) allow students to identify and explain a number of features in the state. For example, rapids visible on the Saluda and Broad Rivers made it easy to conceptualize that the Fall Line Zone was the dividing boundary between the Piedmont and the Coastal Plain regions of South Carolina. A closer inspection of the river systems and drainage patterns of the central part of South Carolina helped explain the distribution of early transportation routes, which resulted in Columbia being selected as the capital of the state. Furthermore,

General William T. Sherman's choice of cannon placement for bombardment of the State Capitol Building near the end of the Civil War made strategic sense when viewed on the aerial photograph.

The SC MAPS curriculum consists of imagery for 18 study sites across the 5 landform regions of the state. A state base map, a state soil and geologic map, and a land use/land cover map are also provided. An extensive teaching handbook, now in its fourth edition, is organized around higher-level thinking activities, a glossary, references, performance tasks, and enrichment activities.

The SC MAPS curriculum helps students develop basic science process skills such as observing, classifying, measuring, inferring, predicting, designing, and

communicating – all skills that can be enhanced by spatial modes of thinking. The program also builds familiarity with the scientific method, including practice in formulating and testing hypotheses.

About Google Earth

Google Earth, a virtual globe software product launched by Google in 2005, was created by Keyhole Inc. and was initially called EarthViewer 3D. Acquired by Google in 2004, the software is based on Keyhole Markup Language (KML), an XML-based language originally developed by Keyhole Inc. Google Earth is a frequently updated computer application that provides opportunities to see Earth’s varied geography from scales that range from aerial to street-level views. Users have the ability to search and browse satellite imagery and digital aerial photographs which are draped over a three dimensional (3D) representation of the Earth. While existing in a two dimensional (2D) environment, it provides an incredibly realistic sense of 3D at certain scales. However,

when the user changes the scale by zooming in, a flattening of the image occurs taking away from this realistic sense of 3D. The Google Earth interface provides a basic set of navigational tools that resemble a dashboard display, which allow the user to zoom in and out, pan, rotate, and tilt the perspective of Earth as well as the ability to measure

distances and view elevation levels. The application’s functionality is magnified by the ability to add layers of data and information to the 3D viewer such as place names, roads, boundaries, photographs, business names, current weather conditions, and 3D buildings to name a few.

Additionally, Google Earth allows users to create content within the application by inserting push-pins or pages with images, videos, or other links. Users may contribute content that others may access by creating vectors (points, lines, and polygons) that record locations of specified features and creating image data that can be viewed on top of the base imagery provided by Google Earth. Developed for use with Google Earth, these user contributions are made through Keyhole Markup Language (KML) files, a file format used for expressing geospatial data. Based on XML standard, KML uses a tag- based structure with nested elements and attributes.

The imagery from Google Earth is not “real-time”, but rather a mosaic of images collected from a variety of sources such as NASA, TerraMetrics, and Digital Globe. Google Earth can be considered a simple form of GIS because it allows the user to input, store, retrieve, display, and output both maps and images. Although simple, Google Earth provides a basic element of GIS functionality for navigation, retrieval and visualization. However, the lack of capacity for geospatial analysis of large amounts of data and the lack of access and control of the underlying data limits Google Earth as a true GIS (Green

and Mouatt 2008). Nonetheless, it has the potential to allow its users to understand geographic concepts such as location, scale, and place by analyzing remotely sensed data and information. Google Earth can be freely downloaded from http://earth.google.com. This website has a wide variety of instructional materials from tutorials to demonstrative videos.

3.3 STUDY SITE AND POPULATION