2012

July 2012

# Using a Smartphone and ArcGIS Online to Teach Accuracy, Precision, GPS, and Critical Thinking

Posted by jkerski-esristaff Jul 18, 2012
Now that it is easy to gather tracks and waypoints on a smartphone and map them in a GIS, it provides a good opportunity to remind students about the importance of being critical of and paying attention to data. I recently went on a walk around a local reservoir and used the Motion X GPS app on my iPhone to collect my track and a few waypoints. I emailed the data to myself and added the GPX file to ArcGIS Online so I could map and examine the track. I made my results public and made it visible below to feature some teachable moments.

Zoom in and examine my track and its attributes. How many times did I walk around the reservoir, and in what direction? What, then, is the line that extends from the reservoir 630 meters to the northwest? When I first turned on the smartphone and began my track, the GPS in the phone did not have enough information to plot my true position. Therefore, the positions plotted were nearby, but not exactly where I was walking until later. Examine the track and its attributes to determine how long I had been walking before the positions become accurate.

These “zingers” or inaccuracies often occur with tracks recorded on a smartphone, and on a standard GPS receiver as well. These results reinforce what we’ve long held as a “best practice”—to wait at your starting point as long as you can after starting your GPS or your Smartphone’s GPS app to ensure the most accurate positions possible on the data you will gather.

After the first 10 minutes, I was quite happy with the accuracy of Motion X GPS, within 1 to 2 meters as compared to the imagery in ArcGIS Online. Using ArcGIS Online you can clearly see each of my three laps around the reservoir. You can even see my attempt to write something in the parking lot using my smartphone using GPS drawing techniques, explained in this video I filmed. Although my letters should have been larger for increased clarity and avoid bumping up against the spatial accuracy of the GPS, I was still pleased with this portion of the experiment.

How might you use GPS apps on smartphones and ArcGIS Online to teach the principles and skills of accuracy, precision, GPS, and critical thinking?

-Joseph Kerski, Esri Education Manager

# From Observations, Curiosity, and the Spatial Perspective to Asking Questions

Posted by jkerski-esristaff Jul 6, 2012
In my last column, I argued that one’s senses, curiosity, and the spatial perspective are essential for understanding our world and for making the most out of field experiences. In this column I wish to make the case that these three things guide the questions you ask. And the questions that you ask are most important thing about any investigation, and about learning.

I also believe that you must be comfortable with the fact that in our complex world, some of the questions cannot be answered without additional investigation, and that some of the questions indeed may never be fully answered. In our world of instant information and standardized testing, quick and easy answers are difficult for many students—and sometimes, instructors—to accept.

Consider a recent video I made on the beach on the coast of the Caribbean Sea where I asked a series of geographic questions. I considered issues in physical geography including sediment transport along coasts, beach sand, storm surges, and hurricanes, and issues in cultural geography including the pros and cons of developing resorts along coasts. I could partly answer some questions I posed in a few minutes, while others I left open for students and instructors to discuss in class.

The questions you ask determine what data and information you will collect, what devices you require, and what methods you will use. We certainly have more means of collecting data than ever before. I believe that geographers from Eratosthenes to Davis would have been thrilled to have and use the tools we have today. We also have an expanding number of ways to map field-collected data. Some of these ways even allow for something that many of us have longed for years to be able to do—to collaboratively and simultaneously gather data in their real-world coordinates by a group of students while out in the field, and have that data automatically appear on a continuously updating map. These can be done using the Student Data Mapper or from shared Google spreadsheets as developed by my colleague Tom Baker, or via editable feature services using ArcGIS 10.1 and ArcGIS Online as shown in the image below.

Yet unless we are curious, using our senses, asking insightful, thoughtful questions, and using the spatial perspective, the effectiveness of even these tools will be limited. What are some of the means you have used to foster good questions to be grappled with?

- Joseph Kerski, Esri Education Manager

By date: By tag: