Latest Contributions by JosephKerski

In my last column, I raised the question about whether a travel column would look different authored from the perspective of a geographer or geospatial professional versus a column authored from the perspective of a journalist. I stated that some similarities surely exist but there are likely to be some key differences. This discussion raises a larger issue: Are all travel writers really geographers? Are all travelers essentially geographers? And, more broadly: With the advent of easy to use geotechnologies that have enabled the general public to use many of the same tools and data that were formerly only used by GIS specialists, does that mean that everyone is now a geographer? In the new book Practicing Geography , my colleagues and I wrote a chapter that asks this very question. These new capabilities reinvoke inherent tensions between the integrity of the field of geography as a discrete academic discipline, on the one hand, and its generalist appeal on the other hand. Although this tension within geography is not new—William Morris Davis reacted to it over one hundred years ago (Schulten 2001)—geography may have never been more prominent within the everyday human experience than it is today . I contend that geography is a three-legged stool. One of the legs of the stool represents deep and rich content knowledge that has accumulated across the millennia but also is forward-looking—envisioning how the world could and should be. The content knowledge includes that about specific places, processes, and phenomena. Another of the legs represents geographic skills—working with scale, maps, imagery, databases, graphs, space and time, movement, dispersion, fieldwork, regions from cultural regions to ecoregions, different perspectives, human-environment interaction, interpreting the past and present and planning for the future, and many more. The skills are used in low tech and high tech situations ranging from interpreting paper maps to operating field probes and performing geoprocessing operations within a GIS environment. The last leg represents the spatial perspective—the unique place-based framework that all geographers bring to any problem that they examine. The spatial perspective is holistic; it is systems-based. What are your thoughts about this topic: Isn’t everyone a geographer? And, what about the increasing number of professionals outside who are incorporating spatial thinking and GIS into their work—in business, history, mathematics, design, biology, engineering and other fields. Are they geographers? Do they need to be geographers? If not, what geographic content knowledge, skills, and perspective do they need to have in order to be effective in their own fields? -Joseph Kerski, Esri Education Manager Reference Schulten, S. 2001. The Geographical Imagination in America, 1880-1950. Chicago, IL: University of Chicago Press. ... View more

I have just created 7 videos totaling 90 minutes of content in a series entitled “Teaching Geography with ArcGIS Online” on the Esri Education Team’s channel, beginning here. This series began with a workshop I taught at the Geographical Association conference. One goal I had in creating the videos is to model how ArcGIS can be used in an instructional setting. The first 3 parts in the series focus on why and how web-based GIS can be used to teach geography, specifically, ArcGIS Online. One reason I chose ArcGIS Online as the main tool is because it allows students, using only a web browser and an internet connection, to quickly investigate real world issues in real places, from local to global scale, developing spatial thinking, critical thinking, and GIS skills and “habits of mind” in the process. These maps can be customized, saved, edited, and shared with others. While each of the first three parts provides practical examples, parts 4 through 7 in the series delve deeply in problem solving with specific issues and themes. Part 4 uses World Bank data and maps to investigate global demographic variables, including birth rate, life expectancy, and population change, by country, from 1960 to the present. Part 5 analyzes the pattern of neighborhood deprivation and poverty, and lack thereof, using the UK as an example. Part 6 asks questions about plate tectonics , including earthquakes, plates, volcanoes, on a global scale, and then analyzes seismic and volcanic activity on a local scale in Texas and on Mount Etna, Italy. This video also shows how to bring in real-time data into the analysis to compare the difference between the last 30 days of earthquakes versus earthquakes dating back hundreds of years. Part 7 discusses three ways to map data that students have collected, by directly adding points, lines, and areas, from data from the field via GPS and smartphones, and from multimedia sources, including video, photographs, sketches, and text onto maps and presentations that tell the story of their project. How could you and your students make use of these videos, and how could you use ArcGIS Online in the classroom? - Joseph Kerski, Esri Education Manager ... View more

Those of us in the fields of geography, education, and GIS can probably name numerous games and activities that we are attracted to simply because there is “something spatial” about them. Some of them may have to do with wayfinding, others with angles and directions, patterns and shapes, distances, adjacency, groups, or may rely on geographic content knowledge. In Monopoly, I always sought houses and hotels on Oriental, Vermont, and Connecticut Avenues simply because I liked where they were positioned on the board. I wasn’t deterred by the fact that they were on the “cheap” side of the board (consequently, I seldom won). I enjoy playing Blokus and putting together jigsaw puzzles because of their spatial aspects (although I never could get the top pieces in the 3-D globe puzzle I helped put together this past New Year’s Eve). Many of us were fond of the blue category in the original Trivial Pursuit game, which was geography (and were subsequently embarrassed whenever we missed a geography question!). I loved the angles and positions in early video games such as Pong and Galaga, and was frustrated by Asteroids largely because it seemed that the scale was wrong. Millions of people play Spatial IQ, Cross Fingers, Glass Tower, and other spatially oriented games on their computers and smartphones daily. And outside, while I found the directions to my one and only road rally game too complicated, I greatly enjoy confluence hunting, geocaching, and earthcaching. A small but growing community of researchers and instructors is exploring how the playing of games can foster spatial thinking, content knowledge, and skills important in science, technology, engineering, mathematics, geography, and GIS. My colleague Dr. Diana Stuart Sinton teaches a class called the “Foundations of Spatial Thinking” as part of the Learning Spatially at the University of Redlands program. One of her assignments to the students is to categorize games and activities in terms of the spatial strategies used, and how the strategies may be relevant for STEM learning. Dr. Ola Ahlqvist has an NSF cyber learning grant to develop and study learning with GeoGames. National Geographic supported Reach The World’s development of geo-games. The world of geospatially-oriented games on smartphones and computers is poised for great expansion, with the inclusion of real spaces and places in these games posing intriguing potential for teaching, learning, and research. Imagine any game scenario not in an imaginary world but taking place using imagery and maps of Davenport, or Shreveport, or anywhere. What are your favorite spatially-oriented games? How might you use games to foster spatial thinking and learning? - Joseph Kerski, Esri Education Manager ... View more

In my last blog post, I mentioned that universities are increasingly thinking about implementing courses entitled “Introduction to Spatial Thinking”. I described a few existing excellent models for such courses, inviting comments from the community. Development of such courses would be hastened by community dialog so that each faculty member does not feel like he or she has to develop such a course from scratch. In this essay, I would like to share components that would valuable in such a course. I believe such a course should include a mix of reflections on readings and videos, and hands-on work with GIS and GPS technologies. An active discussion on the theoretical underpinnings of spatial thinking is necessary, because most students entering such a course most likely have had minimal exposure to geography in the past, and most likely have not purposely thought about the applicability of spatial thinking to their education, career, or life. I would begin with selected videos and essays to foster discussion, including the Geospatial Revolution, GIS Touches our everyday lives, my ArcWatch article Spatial Thinking: Habits of Mind, and my video Why Geography Education Matters. I would access articles on the bibliography on the Esri Education Community from Diana Stuart Sinton, Sarah Bednarz, Reg Golledge, and Phil Gersmehl, among others. Whether face to face or online, I would promote active engagement with geospatial technologies. Easy-to-implement yet powerful activities would use ArcGIS Online, including Earth Quiz: Name that Place, analyzing the distribution of bail bonds and car washes in a metropolitan area, Weird Earth (Using strange and unusual imagery to spark inquiry), Exploring 10 Landscapes (such as eskers, karst, and lava fields), analyzing 10 aspects of water, (including watersheds, wetlands, dams and reservoirs, and oceans), and analyzing demographic components and their implications (such as median age, income, diversity, population density, and population change over time). Over the course of the semester, I would gradually increase the analytical rigor, using ArcGIS for Desktop with selected lessons from the Our World GIS Education books, siting a ski area using GIS, and determining the mean center of population for the USA and for individual states, 1790-2010. I would frequently include getting students out onto the campus or in their own neighborhoods (if the course is online), collecting data, mapping data, hyperlinking text, video, and photographs, and analyzing resulting patterns within a GIS environment. I would require frequent presentations from students, including a presentation at the end of the semester, asking each student: How do you use spatial thinking each day, how have you used spatial thinking to solve three problems in this course, and how will you use GIS in the future? What would you include in a course on spatial thinking? -Joseph Kerski, Esri Education Manager ... View more

Just in time for Earth Day, but suitable for use throughout the year in geography, earth science, environmental science, chemistry, social studies, and in other disciplines is a new lesson that invites students to learn about water using ArcGIS Online. Water is a spatial subject: It easily moves among its solid, liquid, or gas phases on our planet. It flows through oceans, rivers, wetlands, glaciers, and through the hydrologic cycle at different rates. It is affected by long-term climate, everyday weather, hurricanes, landforms, and air pressure. It has been channeled into settling ponds, water treatment plants, fields, irrigation ditches, drainage ditches, canals, reservoirs, and many other means by humans. It acts as a change agent above, on, and below the surface of the Earth, affecting crop yields, aquifers, erosion, floods, stream sediment, soil chemistry, weathering, and much more. Thus, the geographic perspective and GIS are useful to understanding water from local to global scales. These activity use ArcGIS Online, a Web-based Geographic Information System (GIS). Students at the upper secondary/university level can use the lesson, but so can those at the lower secondary level, and the lesson can be modified for primary level. It can be used in formal or informal educational settings and in a whole-class format or in a lab. No previous experience with GIS is necessary but (1) the geographic perspective is important, and (2) a background discussion in the topic investigated will be helpful. For example: “What are watersheds and why are they important?” Through the activities, students investigate major dams and reservoirs, cities along rivers, flood zones, food production, wetlands, and water quality. These include the following questions and assignments: What is the relationship between wind speed and direction to precipitation, current air pressure, temperature, and topography? Using USGS stream gages and weather stations, predict the height of the water in streams where significant precipitation has been occurring. What is the relationship between the location of the gaging station within the watershed and the height of the river? Go outside! Do current weather local conditions match the map you have been examining? Predict tomorrow’s conditions based on the maps you are examining. How could you use ArcGIS Online to teach about water in your instruction? - Joseph Kerski, Esri Education Manager ... View more

Two points in particular struck me as we talked with hundreds of science educators recently at our workshops and exhibit (video) at the National Science Teachers Association’s annual convention. First, ArcGIS Online offers a rich set of data, tools, and capabilities for educators and their students to begin using. And I think an important advantage of ArcGIS Online is that they could begin using it right away. Everyone we talked with could see a connection with what they are teaching, whether in earth science, biology, environmental science, chemistry, mathematics, or other subjects, and analyzing data spatially with ArcGIS Online. That leads me to the second point: Sometimes, the thing that really resonates with an educator is something that might seem small. However, for that educator, it becomes a game-changer for a particular lesson or maybe for the entire course curriculum. It could be a tool, data set, or process that allows them to accomplish more efficiently with GIS than what they could do with paper maps or other physical objects. Using ArcGIS allows students to more quickly move to the analytical phase of a project, working with real data in real contexts. One example of the small-but-big is a discussion I had with an educator from Shoshoni, Wyoming. In this arid part of the mountain west, watering dry fields to grow grass for livestock takes precious water resources. Ants are the one thing that is found in abundance. Ants cause a problem because their large colonies consume a tremendous amount of grass. Eradication with chemicals is ineffective due to the depth of the colonies. Students in the town’s high school routinely get out into the field to measure these ant colonies with GPS and tape measures. When the instructor saw that not only could he and his students use ArcGIS Online to visualize and measure the ant colonies from above, but also geotag and add field observations, audio, photographs, and video to the project, he was overjoyed. As additional fieldwork is conducted, the ArcGIS Online map becomes a living database over space and time. What is the little thing that you learned to do with GIS that caused major changes in what and how you teach? -Joseph Kerski, Esri Education Manager ... View more

A new book from Esri Press entitled Tribal GIS: Supporting Native American Decision Making, will be published in June 2012. In it, tribal leaders tell their stories about implementing and using GIS to address their unique challenges as sovereign Nations. The book covers applications in natural resources and the environment, transportation, cultural and historical preservation, economic development, health, public safety, agriculture, and perhaps most interesting to the GIS education community, two chapters on K-12 and higher education. Showing how tribal governments responsible for the stewardship of their land and resources and the health and well-being of their People use enterprise GIS to make decisions, Tribal GIS supports tribes new to GIS and those with GIS experience. It also will be useful for the general GIS community, showing the many scales and disciplines in which GIS can be applied. It was an honor to work on this book with so many visionary people who are making a positive difference in the lives of people, in their communities and on their lands, and beyond. The book includes dozens of stories written by educators, scientists, administrators, managers, and others, showing the diversity of their backgrounds but also a common vision for the benefits that spatial analysis and GIS bring to their everyday decision making. Editors of the book include Anne Taylor, who coordinates Esri’s Tribal program, David Gadsden, who coordinates Esri’s nonprofit organization program, Joseph Kerski, who serves in Esri’s education program, and Heather Warren, who is the marketing coordinator for the federal government industry at Esri. The education chapters include stories such as students at the Alamo Navajo School collecting water well location and water quality information for the tribal government, students at Santa Fe Indian School measuring soil erosion and analyzing land use, students at Haskell Indian Nations University researching the geology of Antarctica and developing an accessibility map for their own campus, and much more. Space does not permit me to say too much here, but the stories speak for themselves. Pick up a copy of the book, read these stories, and share them with your students. How have the spatial perspective and GIS made a positive difference and aided with decision making? How might you be able to use these stories to generate ideas for your own GIS-based projects? --Joseph Kerski, Esri Education Manager ... View more

The combination of maps and stories, particularly those that show how a city or region has changed over time, is a powerful resource for educators and students of history and geography, researchers, planners, and the general public. Thanks to Esri’s web GIS technologies, these tools are rapidly multiplying, providing a rich set of data to investigate an expanding number of places around the world. One of these is the new Pittsburgh Mapping and Historical Site Viewer. This resource shows how Pittsburgh, Pennsylvania evolved over time, from 22,433 people in 1835 to a major metropolitan area. Explore it at a small scale to get an overview of the metropolitan area. From which point did the city originally begin? Why was its river site simultaneously a blessing to the city but also a danger? What challenges did the local hilly topography pose, and how did the city grow to accommodate it? Explore the site at a large, detailed scale, studying how neighborhoods grow and expand, and how some were planned but never built. Can you find any street names that changed over time? Can you find empty lots that became buildings, schools and churches that opened and closed, and where urban renewal project s cleared neighborhoods, and then later were themselves reconstructed? By browsing through the years via a convenient slider bar at any given location, you will find a cemetery that became a school, the arrival of rail yards and then sports stadiums, and other indicators of how the city has evolved around changes in transportation, industry, and population. You will find photographs linked to specific landmarks and buildings with links to additional information. What was demolished to make way for the Civic Arena in 1961? What sports teams played there? Now that demolition on the arena has begun in 2012, what do you think the neighborhood will look like once it is gone? This resource is largely the result of diligent and careful work by my Esri colleague Chris Olsen. Digital maps were made by cutting and georeferencing hand-drawn paper maps, some more than 175 years old. Chris first examined the wealth of data from the Historic Pittsburgh project, including 46 volumes of Hopkins maps, which he digitally stitched together and compared it to what is on the ground today. He downloaded the raw map plates, cleaned up each image, clipped out the map data, and georeferenced each plate in ArcMap, saving each to the Web Mercator Aux Sphere projection. He then created mosaic datasets grouped by area and year, created MXD and MSD documents using the overlay map at small scales, and switched to the mosaics at large scales. Next, he cached the maps and created the web apps. The feature service on top of the maps was created from the National Registry of Historic Places and the Pittsburgh History & Landmarks Foundation. He is still adding additional content to these. How can you use the Pittsburgh Mapping and Historical Site Viewer in your educational work? - Joseph Kerski, Esri Education Manager ... View more

Take a look at this image. Where is Socotra? Why and how do these trees grow there? Where is the Richat Structure? Why are its origins still a bit mysterious? Why do people create drawings on the landscape that can only be fully appreciated from above? What do you notice about the language of the text, the street names, and the landscape that give clues about the location of this image? Examining the Earth with imagery can be a powerful resource in geography, biology, environmental studies, earth science, and in other courses. Examining imagery can be easily done through the use of ArcGIS Online. The above images are included in an investigation I entitled “Weird Earth.” This investigation includes the images above, as well as a giant lizard, mazes, an erupting volcano, the walled city in the mist, and much more. Why Weird Earth? First, fascinating patterns, places, and phenomena abound on our planet, and some are just plain weird. Examining the bizarre is an excellent way of sparking student interest. As images are examined, the door for inquiry is opened: What physical and environmental factors caused the land and vegetation to look as it does? What do human-created objects on the landscape say about the culture and language there? What will these images look like tomorrow, in 10 years, in 100 years? Second, I wanted to illustrate that the presentation mode in ArcGIS Explorer Online is an effective and easy-to-use technology to teach such concepts. View the metadata here.  You can also watch the investigation as a video with the introduction here, the investigation here, and the answers and final discussion here. The presentation is dynamic: You can change the scale and basemaps from satellite images to topographic maps, street maps, and much more, while posing questions, fostering deeper inquiry into places and the processes at work behind those places. For example, when you engage students in examining Socotra using the above slide, zoom in to examine hills versus valleys and the amount of tree cover on each. Zoom out until someone recognizes the island’s location. Then discuss the effect of isolation, latitude, and altitude on the vegetative cover, and why 1/3 of the species are endemic to the Socotra Islands. Change the basemap to topographic to determine the height of the mountains and the depth of the valleys. You can add ecoregions and climate map layers and discuss how these influence the bizarre trees and other species on the island. You can add a population layer and discuss the settlement pattern of the island. Thus, these are by no means static slides. Even calling them “slides” is really a misnomer. Even better, create your own investigations focused on other processes, specific themes, specific regions, or your own community. What do you consider unique or “weird” about your own community? How might you use the concept of Weird Earth in your own teaching and learning? How can you use ArcGIS Online to investigate what is strange and interesting about your own community? - Joseph Kerski, Esri Education Manager ... View more

A book I co-edited with Dr. Andy Milson and Dr. Ali Demirci has just been published by Springer, entitled International Perspectives on Teaching and Learning with GIS in Secondary Schools. This is the first publication to collate a broad international perspective on the pedagogical value of GIS technology in classrooms, and offers an unprecedented range of expert views on the subject. For more information and to read sections of the book online, see the publisher's site. The authors created a series of five videos describing the book. This book brings together authors from 33 countries who profile the current status of GIS in secondary school teaching and learning in their country. We have been honored to have worked with each of our authors and to hear their inspiring stories. Each chapter includes a summary of the country’s educational context, a case study illustrating how GIS is used in secondary schooling, and an assessment of the opportunities and challenges in teaching and learning with GIS now and in the future. We are honored that Roger Tomlinson wrote the Foreword. The editors wrote a synthesis chapter where we reflect on the progress made in teaching and learning with GIS over the past 20 years, the key trends for the remainder of this decade, and make heartfelt recommendations as to what needs to happen to meet the goal of engaging all students in thinking spatially. The book demonstrates that GIS is not only a technological tool to be used in the classroom, but also a catalyst for motivation, encouragement, and cooperation in understanding and solving global problems. Geographic Information Systems (GISs) have revolutionized the way people explore and understand the world around them. The capability they confer allows us to capture, manage, analyze, and display geographic data in ways that were undreamt of a generation ago. GIS has enabled users to make decisions and solve problems as diverse as designing bus routes, locating new businesses, responding to emergencies, and researching climate change. GIS is also having a major impact in the classroom. Students and teachers around the world are using this significant emerging technology in the secondary school classroom to study social and scientific concepts and processes, to broaden their technical skills, and to engage in problem solving and decision making about local and global issues. We look forward to assembling a panel of the book’s authors at upcoming conferences, including that of the Association of American Geographers and the Esri Education Conference. How might you use this book to make a case to your colleagues and administrators about the value of GIS in education? - Joseph Kerski, Esri Education Manager ... View more

In a thought-provoking article, Kim Kastens states that “learning to learn from data” is a necessary part of everyone’s education, but not a typical part of everyone’s education. Making it a typical part is a significant challenge. Kastens describes the difference between learning to look up information on a graph and seeing and interpreting patterns in data. How can we help students see patterns and trends that data represent? One way to see patterns in data is through the use of Geographic Information Systems. GIS was created to be a tool with which to investigate data. Isn’t it easier to see the relationship of birth rate to life expectancy, or tsunami damage based on proximity to coasts, with a map rather than only a data table? GIS gives the instructor and student the ability to see the relationship between the map and the underlying database. Instructors using GIS focus on problem-solving, inquiry-driven pedagogical techniques that use real-world data to analyze spatial patterns on scales from local to global. They focus on classroom, community, and careers, promoting scholarship, citizenship, and artisanship. Dr Kastens’ article discusses the use of student-collected data. Students can collect their own data on tree height and species, pH in streams, or other phenomena using probes, GPS, or smartphones. They can input that data into a GIS for analysis as easy as dragging-and-dropping their files into ArcGIS Online. GIS allows for graphing, summarizing, and answering questions such as “What is the average soil moisture on the south-facing versus the north-facing slopes?” “What is the average height of pine versus spruce trees?” “How many earthquakes occurred in 2011 within 100 km of subducting plate boundaries?” Kastens invites students to dig into data and think critically about where it comes from. GIS is nothing without data. Students using GIS develop critical thinking skills about data – its imperfections, its limitations, its gaps, and its use, rather than just “accepting it because it is on the Internet!” or thinking “because it is on a map, it is perfect.” Nowadays, it is easier than ever to use GIS in the classroom. One excellent place to start is http://www.arcgis.com to create and analyze maps of recent earthquakes or landslides around the world, soils or biomes in a region, or food expenditures in a metropolitan area. These maps can be saved, shared, and built upon. How could you use GIS to learn with, from, and about data? - Joseph Kerski, Esri Education Manager ... View more

In my last blog, I discussed a new lesson and data set, entitled “Population Drift: Mean Center Analysis 1790-2010” in the ArcLessons library, which uses spatial analysis, spatial statistics, and GIS to determine and analyze the population centers of the USA and individual states over space and time, from 1790 to 2010. One of the most fascinating parts of this lesson is examining the movement of state population centers. This map shows the movement of mean center for each of the 48 states from 1900 to 2010, with the 1900 center shown as a blue square and the 2010 center shown as a red square. Nevada’s mean center of population moved the farthest, making a beeline north to south from the mining areas near Virginia City in 1900 toward fast-growing Las Vegas. Similarly, the influx of residents to southern California and the decline of mining tugged California’s mean center toward Los Angeles, though the San Francisco Bay cities kept the center from moving as much as in Nevada. Colorado’s mean center moved from the Rocky Mountains to the Great Plains, inexorably toward Denver. In Kansas, the center moved west until 1920 as the high western plains were settled, but then reversed as a result of high plains population loss beginning with the Dust Bowl and continuing to the present day. Why did Virginia’s center move north? Why did some state centers move very little? In which state is the population center the furthest from its geographic center? How might you use this lesson and data set to teach about the many economic, political, demographic, and perceptual forces that pull on the population center of each state? Where will these centers move in the future? How might you use these same techniques to analyze how the population center of a metropolitan area or a county moved over time? How might you use GIS to determine where the mean center of ethnic groups in your community or people of specific age ranges are located? Why are these centers not necessarily in the same location as the mean center for the whole population? - Joseph Kerski, Education Manager ... View more

Analyzing the Mean Center of Population for the USA and for Individual States, Updated for ArcGIS 10 and Census Year 2010 A new lesson, entitled “Population Drift: Mean Center Analysis 1790-2010” in the ArcLessons library (search on Population Drift), invites students to use spatial analysis, spatial statistics, and GIS to determine and analyze the population centers of the USA and individual states over space and time, from 1790 to 2010. This lesson was recently updated to include 110 in-depth questions, a very rich set of data including the new 2010 county population figures, and to use the powerful spatial statistics tools in ArcGIS 10. The objectives of this lesson are to 1) Understand the definition of and application of mean center and weighted mean center; 2) Understand the definition and use of a population weighted mean center in a GIS environment; 3) Learn how to calculate mean population centers for the USA and for individual states using GIS tools; 4) Understand the magnitude and direction of movement and key reasons why the US population center moved from 1790 to 2010; and 5) Analyze how and key reasons why population centers for individual states moved from 1900 to 2010. Skills include calculating mean centers, selecting and using spatial and attribute data, and symbolizing and querying maps. The investigation of population change and population centers naturally lends itself to discussions of job creation and loss, economic conditions, perceptions of place, the evolution of agribusiness and rural outmigration, urbanization, suburban sprawl, sunbelt migration, changes in the median age, changes from industry to services, international migration to the USA, and a whole host of other issues. Examining the population center for individual states allows students to consider how these issues operate on a state scale. The Census Bureau recently published information on the location of the new 2010 USA center of population, as well as a series of interactive maps showing the 1790-2010 movement, on: http://2010.census.gov/2010census/data/center-of-population.php. Linked to the page is a series of videos from Census Bureau Director Robert Groves who discusses the movement of the population center. These interactive maps and videos provide excellent supplementary materials to the ArcGIS-based lesson. How might you use this lesson to teach about the many economic, political, demographic, and perceptual forces operating over the decades? -Joseph Kerski, Education Manager ... View more

Recently, I wrote about my comparison of the horizontal position obtained from a consumer-grade GPS receiver versus that obtained on a SmartPhone. Specifically, I compared a Garmin GPS 76 to an iPhone 4. The position recorded on my iPhone was consistently tens-of-meters off from the position recorded with my GPS receiver. Thus far, it appeared that my position as recorded by my GPS receiver is far more accurate than that from my iPhone. However, this was not the end of the story. In the field, I switched to the map view on my phone, and the blue dot marking my current position was not hundreds of meters away, but just a few meters from where I was standing. I took a photograph here and emailed it to my PicasaWeb account using the procedures I wrote about in a previous blog column. This photograph was geotagged at 39.680000 north latitude, 104.962667 west longitude, which turned out to be only 6.21 meters away (this time to the southwest) from my position as recorded by the GPS receiver. Interesting! This means that the SmartPhone was indeed recording an accurate position, but perhaps the app used to capture that position may have compromised that position. The map I created from ArcGIS Explorer Online below shows my hyperlinked photograph very near to the position where I conducted the experiment, and several blocks to the northwest is the position recorded by the default compass utility in my phone. Zooming in, Pushpin A at the end of the green line points to where I stood at the brick wall on campus. Pushpin B, 5.23 meters north-northwest, is the position recorded with my GPS receiver, and Pushpin C, 6.21 meters to the west-southwest, is the geotagged position recorded in the photograph I took at that spot. Your results will vary with the tools, including the types of WebGIS, GPS, and SmartPhone used. For example, a higher-end GPS such as a Trimble or TopCon will surely provide better horizontal accuracy. Also, would my iPhone position have been any better if I had used a GPS app instead of the default compass tool in my phone? All of these technologies will continue to undergo rapid change, providing ample opportunity for further experiments. These types of experiments connect mathematics, GIScience (including discussion on datums, coordinate systems, and data quality), and geography. How might you turn these activities into teachable moments and activities? - Joseph Kerski, Education Manager ... View more