# Remote Experience Authoring Language - REAL

## Basic Proposal Information

  ---------------------- ------------------------------------------------
  Title:                 Remote Experience Authoring Language - REAL

  Brief Description:     The Remote Experience Authoring Language -REAL-
                         and associated tools will enable educators to
                         easily create remote experiences using NASA
                         data. A collaboration with Platform Digital,
                         LLC, the creator of REAL, will result in tools
                         and standards for the creation of NASA remote
                         experiences.

  Partners:              JPL, Goddard, Carnegie Mellon University,
                         Platform Digital, LLC

  Center:                Langley Research Center

  Endorsee:              Jeff Seaton

  Primary Contact Name:  Jeff Seaton

  Primary Contact Phone: 757-864-6687

  Primary Contact Email: <j.m.seaton@larc.nasa.gov>

  Secondary Contact      Peter Copin
  Name:                  

  Secondary Contact      412-268-1565
  Phone:                 

  Secondary Contact      <coppin@cmu.edu>
  Email:                 
  ---------------------- ------------------------------------------------

## Milestones

Note---Figures for this proposal are available on the web at

<http://occipita.cfa.cmu.edu/eventscope/ltp/>

For more information on the industry and academic partners see:

[www.platformdigital.com](http://www.platformdigital.com/)

[www.eventscope.org](http://www.eventscope.org/)

### MILESTONES:

For detailed project schedule, including milestone explanation and
schedule, please refer to section 4, Project

Feasibility. Phase I milestones are listed below.

MILESTONE 1: Review Prototype Implementation

MILESTONE 2: Requirements Document Complete

MILESTONE 3: Detailed Project Plan Complete

MILESTONE 4: Design Document Complete

MILESTONE 5: Internal Walk-Through

MILESTONE 6: External User Test

MILESTONE 7: Final Report

## Project Purpose

### Educational Needs

A vast amount of data about our planet Earth-its land, oceans,
atmosphere, and life-is being continuously collected by satellites and
other sensing devices. Of that data only a limited amount of it is
widely available to educators and the public. Most of it is presented
through the traditional formats of atlases and textbooks, and more
recently through web pages.

Current desktop computer technology makes it possible to present Earth
data in a new format which has substantial advantages over traditional
formats:

The three dimensional structure of land, water, and atmosphere can be
directly represented and navigated using real-time 3D graphics. ·Size
relationships between different Earth features can be directly
understood by smoothly zooming from a view of the whole planet down to
smaller details. ·Interactive measurement tools make it easy to
accurately quantify the length and area of Earth features. ·Earth
features that change over time can be represented directly through
animation. ·Up-to-date data can be retrieved through an Internet
connection. We can answer the questions: What did the Earth look like
over the last week? What does the Earth look like right now? ·Data sets
can be dynamically layered on top of each other by the user. The student
is not limited to data comparisons and analysis that are predetermined
by the data publisher. ·Collaboration, teaching, and learning can be
facilitated by 3D annotation tools that allow students and teachers to
draw directly on the 3D models of the Earth that they are looking at.
Students and teachers can share their annotations and commentary with
each other over the Internet.

In comparison, the traditional paper based formats for Earth data
require compromises to accommodate the restrictions of the medium. Web
pages suffer from the same restrictions, for as the term "page" implies,
web pages are essentially a simulation of the traditional paper medium:
static, 2D, and non-interactive. Efforts to make web pages interactive
are hindered by the fact that all web interactions require a round trip
from the user's computer to a web server and back, and hence the
interactions are inherently slow and low bandwidth. However by
developing a software system that makes use of current computer graphics
and networking technology on inexpensive desktop computers, it becomes
possible to represent the Earth in a much more direct, natural, clear,
and complete way.

Such an Earth software system addresses the following educational needs:

Supports diverse learning styles for Earth science education, by
facilitating experiential, inquiry-based, collaborative, and visual
learning.

-   Up-to-date data allows new research and current events to be
    incorporated into curricula. Students' experiences inside and
    outside the classroom can be directly connected. For example
    students can use the software to understand the current local
    weather in terms of larger regional weather patterns.

-   Provides visualizations of Earth data on desktop computers that are
    affordable to schools, science centers, and libraries. In the past,
    similar visualizations were available only on specialized expensive
    hardware. These visualizations allow students to understand Earth
    science concepts in a clear and direct way.

-   Addresses the Learning Technologies Project Pillars of Interactive
    Environments and Immersive Technology Experience by delivering real
    NASA satellite data to an immersive 3D interactive interface over
    the Internet.

-   Supports e-Government initiatives of NASA and the Federal Government
    by providing NASA Earth data online in formats that directly serve
    the needs of NASA education customers. ·Engages students with rich,
    interactive content that is current and relevant to their world.
    Promotes interest in NASA Earth science activities.

### Proposed Solution

The Earth Portal system, a software system that delivers continuous
streams of NASA Earth satellite data to an immersive 3D visualization
and collaboration interface running on inexpensive desktop computers.
The system includes the Earth Authoring Tool allowing NASA's educators,
mission outreach teams, and scientists to create customized public Earth
Portals for NASA education customers such as K-12 students and teachers,
science centers, public libraries, and university researchers. Earth
Portals provide interfaces and curricula for the data streams that are
tailored to meet individual requirements and outreach goals for
particular missions. The real satellite data used by the system is
supplied by NASA Distributed Active Archive Centers (DAACs) that
process, archive, and distribute Earth science data.

\[See block diagram of system architecture at
<http://occipita.cfa.cmu.edu/eventscope/ltp/>\]

The system is made up of the following components:

-   NASA DAAC Servers deliver raw Earth data from satellites to the
    Earth Reality Server.

-   The Earth Reality Server aggregates data retrieved from the NASA
    DAAC servers. It converts data to a standardized format and stores
    the data. Then the Earth Reality Server will deliver live streams of
    Earth data to the Earth

Navigation Tool and the Earth Authoring Tool using efficient formats and
protocols.

-   The Earth Authoring Tool allows lessons to be created for the Earth
    Navigation Tool. These lessons customize the Earth Navigation Tool's
    interface and present an interactive sequence of Earth data views
    with annotations and commentary.

-   Earth Portals are entry points to the system for the public,
    educators, and students. An Earth Portal can simply be a web page
    that makes Earth Navigation Tool available for download along with
    particular lessons.

-   The Earth Navigation Tool provides an immersive 3D visualization and
    collaboration interface to the end users. It loads and displays
    lessons created with the Earth Authoring Tool. But the Earth
    Navigation Tool always retrieves actual Earth data directly from the
    Earth Reality Server, so it will always be possible to see the most
    current data, including data that arrived after the lesson was
    created

\[See image of the Eventscope Navigation Tool at
<http://occipita.cfa.cmu.edu/eventscope/ltp/>\]

### Outcomes

-   An operational prototype of NASA DAAC servers that transmit data to
    the Earth Reality Server. The implementation of these servers could
    involve simply configuring existing servers, or could involve
    developing new server software.

-   An operational prototype of the Earth Reality Server which retrieves
    data from NASA DAAC servers and streams it to the Earth Authoring
    Tool and the Earth Navigation Tool.

-   An operational prototype of the Earth Authoring Tool which allows
    customized lessons for Earth Portals to be designed.

-   An operational prototype of the Earth Navigation Tool which allows
    lessons to be loaded, including a 3D collaborative interface to live
    Earth data.

-   A usability study of the software system. Actual middle school
    students will test the software. The results of this study will be
    used to plan future enhancements and revisions.

2.d. Communities Served

In Phase II, a diverse range of communities will be served. The software
and curriculum will be deployed to urban, suburban, and rural schools.
Carnegie Mellon University's EventScope project has a track record of
deploying software and curriculum into diverse communities. Using
lessons developed using the REAL Authoring Tool from Platform Digital
LLC, the EventScope project has deployed remote experience software and
curriculum to:

-   Over 1,800 students total

-   Over 500 underserved students

## Innovation

The following aspects of the project are innovative:

-   Providing 3D visualization of Earth data on inexpensive desktop
    computers.

-   Providing a unified standard interface to large amounts of NASA
    Earth data.

-   Using network streaming technology to provide users with live
    updates of Earth data.

-   Providing interface customization and curriculum development for
    different groups of users through the Authoring tool.

-   Enabling education and collaboration through 3D annotation and
    commentary tools.

3.b. Related Projects

NASA Goddard Scientific Visualization Studio
(<http://svs.gsfc.nasa.gov/)-This> facility has created many innovative
visualizations of Earth data and Earth processes. This work has
primarily been developed on specialized graphics hardware for scientific
users, so it does not scale easily to inexpensive desktop hardware with
student users. The Scientific Visualization Studio web site makes a wide
variety of advanced Earth visualizations publicly available in the form
of images and movies. This content is not interactive. In contrast, the
Earth Portal system will provide interactive 3D visualization of Earth
data on inexpensive desktop computers.

The Digital Earth (<http://www.digitalearth.gov/)-This> is a broad
international initiative to make digital representations of Earth widely
available. Within the United States, NASA has been identified as the
lead agency for the national Digital Earth Initiative. The Earth Portal
system will promote the goals of the Digital Earth Initiative.

The GLOBE Program: Global Learning and Observations to Benefit the
Environment (<http://www.globe.gov/)-This> program engages students in
the scientific process by allowing them to collect and analyze their own
Earth environmental data. Students all over the world submit data to the
GLOBE web site where the data is aggregated. On the web site the
combined data can be searched and visualized as static 2D maps and
graphs. The Earth Portal system will fulfill a different role in that it
will provide NASA satellite data through a 3D interactive interface.
Although not part of this proposal, it would be possible to extend the
Earth Portal system to provide enhanced visualization of student
collected data in addition to NASA satellite data.

Earth Observatory (<http://earthobservatory.nasa.gov/)-This> is an
online NASA publication which provides news about current NASA Earth
science research. The web site has images and interactive QuickTime
movies derived from NASA satellite sensor data. In comparison, the Earth
Portal system will provide more extensive interactive visualization
capabilities, such as 3D annotations and free 3D navigation to allow the
Earth to be seen from any point of view. The Earth Portal system will
also allow larger data sets to be visualized in more detail.

Signals of Spring (<http://www.signalsofspring.com/)-This> is a
web-based package that provides training for teachers and curriculum
materials. Students work in teams using Earth image data from NASA and
other satellites to explain the migration of land and marine animals
that are tracked by satellites. Earth and animal data is presented on
the web site in static images. Some simple interactivity is implemented
to select and navigate the data. In comparison, the Earth Portal system
will provide more extensive interactive visualization and collaboration
capabilities. Although not part of this proposal, it would be possible
to extend the Earth Portal system to provide enhanced visualization of
animal tracking data.

Starry Night (<http://www.starynight.com/)-This> is a commercial
astronomy software application published by Space.com, Inc. which
provides detailed interactive 3D views of the night sky. It is somewhat
related to the Earth Portal system in that it runs as a native
application on the user's computer which opens up possibilities for
richer interaction and more detailed visualization of scientific data
than is possible through a web interface. It is complimentary to the
Earth Portal system in that it provides a simulated view looking out
toward the stars, while the Earth Portal System provides a simulated
view looking in toward the Earth. Starry Night also demonstrates the
commercial viability of software that provides visualizations of real
scientific data in the home enthusiast and education markets.

## Diffusion Potential

### Replication

The Earth Portal system is a general-purpose Earth data visualization
system that can be reused in a variety of different contexts to meet the
needs of a range of user communities. Flexibility of the system is
enabled by the following features:

-   General mechanisms for retrieving, storing, transmitting, and
    visualizing Earth data will be developed. Existing standards will be
    used and new standards established as needed. The software will not
    be designed to display only a few handpicked Earth data sets, rather
    it will be designed as a general framework that allows easy
    importing of new data sets.

-   The Earth Authoring tool will allow customized lessons and
    presentations to be constructed from the raw data. This allows Earth
    Portals to be developed which meet the needs of a range of user
    communities.

This flexibility in the software system will enable wide replication of
the initial deployment. This flexibility will also allow for
applications of the system that were not part of the original plan.

### Other Communities

As all human beings are citizens of Earth, we all have some need to
understand our planet. The Earth Portal system will directly meet this
need by providing live visualizations of the current state of our
planet. The initial deployment of the Earth Portal system will focus on
middle school students in the United States. The following additional
communities would have particular interest in the Earth Portal system,
and could be included in future customizations and deployments of the
system:

-   Elementary, high school, and undergraduate students. Earth Portals
    can be customized to meet the needs of many levels of education.

-   International students around the world.

-   Scientists, graduate students, and other researchers who need access
    to the latest Earth data for current research.

-   Professionals engaged in environmental resource management and land
    use planning who need detailed current environmental and land use
    information.

-   Home enthusiast users and lifelong learners, similar to amateur
    astronomers, who want to see and understand our Earth to satisfy
    their own curiosity and engage in the excitement of discovery.

In addition, the Earth Portal system could be adapted to present a
digital model of planets other than Earth. For example, by using data
returned by the Mars Global Surveyor, Mars Odyssey, and other NASA
spacecraft, the system could be adapted to visualize the entire globe of
Mars. This would extend the audience of the system to whole new
communities of educators, scientists, and professionals focused on Mars
instead of Earth

### Cost-Effectiveness

The development of the Earth Portal system will primarily be
cost-effective because it will not be developed from scratch; it will be
an evolutionary growth of software that has already been developed by
two of the partners: Platform Digital LLC and the Carnegie Mellon
University EventScope project. Platform Digital LLC developed the REAL
Authoring Tool which allows remote experienced based 3D interactive
lessons to be designed. The REAL Authoring Tool was developed under the
NASA SBIR 2001 program. The EventScope project developed the EventScope
Navigation Tool which allows students to navigate through the lessons
created by the REAL Authoring Tool. Between these two software tools,
the following functionality has already been implemented, tested, and
deployed to many middle schools:

-   Importing a planetary data set (Mars Global Surveyor MOLA data in
    PDS format) and using it to generate interactive 3D models of
    planetary terrain.

-   Flexible navigation of 3D planetary models.

-   3D annotation and collaboration tools. Students and teachers can
    draw their own annotations on the 3D models and write text
    commentary and share their work by saving it to disk or a network
    file server.

-   Customized lessons can be configured using the REAL Authoring Tool.

In addition, the CMU EventScope project has already begun a prototype of
live data streaming for the Navigation Tool. This effort is currently
being directed toward Mars rover data streams. The architecture
developed and lessons learned will support the development of live
streaming of data from Earth satellites.

In summary, the Earth Portal system will provide a revolutionary user
experience in a cost-effective and straightforward way by making an
evolutionary enhancement of technology that has already been developed.

### Improvements on Existing Approaches

The Earth Portal system improves on existing web interfaces to Earth
data. The web architecture limits interactivity and bandwidth because
most of the computational burden is placed on the web server, not on the
user's computer. Each interaction requires a round trip to the web
server and back, introducing delays. The Earth Portal system avoids
these limitations because the Earth Navigation Tool runs as a native
application on the user's computer. The Earth Portal system will have
the following features which are generally not available through
web-based interfaces:

-   3D interactive navigation through large data sets

-   Animation

-   User selected layering of multiple data sets

-   3D annotation and collaboration

-   Live updating of data

While some web pages do implement a few of these features, none of them
implement all of them.

The Earth Portal system also improves on the partners' existing
software-the REAL Authoring Tool and the EventScope Navigation Tool. The
Earth Portal system will make the following primary enhancements to this
software:

-   Ability to load Earth data sets

-   User selected layering of multiple data sets

-   Display of the time component of data sets using animation

-   Whole planet view with smooth navigation to higher levels of detail

-   Live updating of data

### Information Sharing

Information about the Earth Portal project will be shared through
education and technical conferences and publications as well as NASA
internal publications.

## Project Feasibility

### Technical Approach

Principal requirements that influence the technical approach are:

-   The Earth Navigation Tool must run with reasonable performance on
    desktop computers that are commonly available in schools.

-   The Earth Reality Server and Earth Navigation Tool must communicate
    with reasonable performance through Internet connections that are
    commonly available in schools.

Consequently, a lot of activity of each component of the Earth Portal
system is concerned with streamlining and optimizing the transmission
and visualization of large data sets.

To handle limited network bandwidth, limited disk space on school
computers, and limited memory on school computers, a multi-level caching
system will be used:

-   The Earth Reality Server will have a large amount of disk storage
    and will be able to store the current set of all Earth data for the
    system. The Earth Reality Server will deliver streams of data in an
    efficient format to the Earth Navigation Tool. Only the portion of a
    data set that is actually needed by the Earth Navigation Tool will
    be delivered.

-   The Earth Navigation Tool will cache data on its local disk, so that
    it does not have to be reloaded from the Earth

Reality Server each time it is accessed. Older data will be removed as
needed from the local disk to limit the amount of local disk space used.

-   The Earth Navigation Tool will load data into memory from the local
    disk only as needed for the user's current view. For example a
    detailed model of the whole Earth that is too big to fit into the
    computer's memory can still be visualized effectively by only
    loading the portion of the Earth that the user is currently looking
    at.

3D visualization performance will be optimized for classroom computers
by implementing general purpose view culling and level of detail
mechanisms for Earth data. View culling mechanisms avoid spending time
drawing objects that are actually completely off the screen. Level of
detail mechanisms adjust the detail shown in an object depending on how
big the object is in the user's view. Distant or small objects don't
need a lot of detail.

Additional considerations for the technical approach are the programming
language and 3D graphics and networking libraries to be used for
implementation. Currently the REAL Authoring Tool and the EventScope
Navigation Tool are written entirely in the Java programming language,
using the Java 3D library for 3D graphics. Therefore Java and Java 3D
are likely candidates for implementation of the Earth Portal system, but
other candidates such as the C++ language with the OpenGL graphics
library will be considered as part of the prototyping and high-level
design phases of development. There are a number of trade-offs between
the different language environments to be analyzed, including reuse of
existing code, performance, portability, flexibility, and speed of
development.

### Team Qualifications

The Earth Portal system will be developed by Platform Digital LLC in
collaboration with NASA Langley Research Center. Platform Digital has a
track record of developing successful 3D telepresence interfaces to NASA
data. The EventScope Project at Carnegie Mellon University has used
Platform Digital's 3D interactive software to deploy curriculum based on
real NASA data to over 1,800 middle school students.

Due to the length limitation for each section of this proposal,
biographical information for key project personnel is available online
at <http://occipita.cfa.cmu.edu/eventscope/ltp/>.

### SCHEDULE AND MILESTONES

Preliminary Project Plan: Initial budget and schedule for the Project.
Duration: 1 week

Prototype Requirements: Determine technical and user interface issues to
be resolved by prototyping. Consider requirements for communication
between Langley DAAC server and Earth Reality Server. Duration: 1 week

Implement Prototypes: 6 weeks

MILESTONE DUE, Week 8: Review Prototype Implementation

Requirements: Determine requirements for the final system, including
functional, usability, and performance requirements. Duration: 2 weeks

MILESTONE DUE, Week 10: Requirements Document Complete

High-Level Design: Determine the overall architecture of the system and
the interface design. Duration: 2 weeks

Detailed Project Plan: Revise and add detail to the project plan based
on the requirements and high-level design. Duration: 1 week

MILESTONE DUE, Week 12: Detailed Project Plan Complete

Detailed Design: Design individual components of the system and
determine details of the interface design. Do additional prototyping as
needed to resolve technical and user interface issues. Implementation of
the code framework for the overall architecture can also begin during
this phase. Duration: 8 weeks

MILESTONE DUE, Week 20: Design Document Complete

Implementation: Implement complete design. Duration: 8 weeks

Integration: Integrate all components, focusing especially on
communication between the Langley DAAC server and Earth Reality Server.
Duration: 4 weeks

Testing: Test the integrated system. Revise the design and
implementation as needed to fix problems. Duration: 4 weeks

MILESTONE DUE, Week 32: Walk-Through: To begin the testing phase, the
whole team walks through the major functions of the system together to
observe any problems or outstanding issues.

MILESTONE DUE, Week 34: User Test: Midway through the testing phase, the
software is tested by real users-students-to determine any outstanding
usability issues.

MILESTONE DUE, Week 36: Final Report

Phase I of the Earth Portal project will take a total of 37 weeks (8.5
months) to complete.

### Privacy

We will implement a privacy policy to protect the privacy of individual
users. As part of the testing of the Earth Portal system, it may be
useful to automatically gather anonymous usage information from the
Earth Navigation Tool, similar to the way web servers record anonymous
statistics about every web page accessed. If such usage data is
transmitted and recorded from the Earth Navigation Tool, a notice will
be provided informing users what data is being transmitted. In no case
will personally identifiable information be transmitted to such an
automatic data collection system.

We will in particular respect all school policies regarding the privacy
of students.

### Budget

Please refer to section 1 for a complete budget summary.

In the past, the CMU-based EventScope project has obtained numerous
awards of non-federal matching funds for NASA-funded programs. For
example, two-thirds of the cost of the NASA LEARNERS-funded EventScope
project was financed by philanthropic foundations, including, the Heinz
Endowments, and the Buhl, Grable, Richard King Mellon and Laurel
foundations. In addition, Platform Digital LLC, the commercial spin-off
from the CMU EventScope project, gained finances from the NASA SBIR
program and is in continued discussions to gain additional matching
funds. Platform Digital will provide royalty-free licenses to CMU
EventScope in 2002.

For this proposed effort, Platform Digital is coordinating financial
support with Innovation Works, a Pittsburgh-based investment group with
a mission to revitalized entrepreneurial efforts in Western
Pennsylvania. Additionally, CMU EventScope has a proposal under review
by the Richard King Mellon Foundation, which would result in a \$100,000
contribution towards this effort. Other resources include future SBIR
opportunities and the Pittsburgh Digital Greenhouse, a state-financed
organization founded to revitalized business in the Pittsburgh area.

## Partnerships

### PARTNER: Platform Digital LLC (Industrial). 

ROLE: Designs and implements the Earth Reality Server, the Earth
Authoring Tool, and the Earth Navigation Tool. Collaborates with NASA
Langley to design and implement communication between DAAC servers and
the Earth Reality Server.

CONTRIBUTION: Provides the previously developed REAL Tool software
architecture. (in-kind) BENEFIT: Positions itself to become a customer
to NASA through the enhancement of its existing Authoring Tool.

### PARTNER: Carnegie Mellon University (Academic)

ROLE: Provides the EventScope viewer. Will run project classes at CMU
for rapid prototyping.

CONTRIBUTION: Licenses REAL Tool enhancements, model optimization tool,
and Rover Streaming protocols to Platform Digital. (in-kind)

BENEFIT: CMU has an equity stake in Platform Digital. Additionally this
creates an opportunity to further utilize

CMU's EventScope public portal.

### PARTNER: NASA Langley Research Center

ROLE: Provides project oversight. Collaborates with Platform Digital to
design and implement communication between DAAC servers and the Earth
Reality Server. Supplies Earth data from DAAC servers.

CONTRIBUTION: Earth data sources; project management; input relating to
educational impact and evaluation

BENEFIT: NASA in general and Langley specifically gain the Earth Portal
system which allows Earth data to be more accessible through customized
portals that meet the needs of particular NASA customers including K-12
education and the general public.

### PARTNER: NASA Goddard Space Flight Center

ROLE: Supplies additional Earth data from DAAC servers. David Herring of
Goddard will work with the project to supply data sources such as NASA
Earth Observing System.

CONTRIBUTION: Earth data sources

BENEFIT: NASA in general and Goddard specifically gain the Earth Portal
system which allows Earth data to be more accessible through customized
portals that meet the needs of particular NASA customers including K-12
education and the general public.

## Evaluation

### Outcome Evaluation

For Phase I of the Earth Portal project, outcomes will be evaluated by
internal tests and by a user test with middle school students.

One purpose of this testing is to verify that the prototype Earth Portal
system meets the requirements that are enumerated during the development
process. The requirements will in turn be based on the outcomes stated
in this proposal.

There are three major categories of requirements that will be verified:

-   Functional requirements-Does the system perform all the functions
    that are required?

-   Performance requirements-Does the software run fast enough on
    desktop computers commonly available in schools? Does it run
    reliably?

-   Usability requirements-How do middle school students experience the
    software? Are interactions confusing or clear? Is the software
    frustrating or fun to use?

Another purpose of these tests, in particular the user tests, is that
they will give us information to shape the future course of the project
and improve future outcomes by answering questions such as:

-   What aspects of the interface are engaging and what aspects are
    difficult or boring and could be improved?

-   How do students learn most effectively from the system? What aspects
    of the system should be changed or enhanced to improve student's
    learning?

For Phase II of the project, outcome evaluation would include much more
extensive evaluation of the educational impact of the Earth Portal
system and associated curriculum through pre- and post-testing.

### Performance Goals

Our development methodology and outcome evaluation are validated based
on two basic performance goals:

-   Students are engaged by the Earth Portal system. Students experience
    Earth science in a way that is interesting, worthwhile, and relevant
    to them.

-   Students learn effectively through curriculum based on the Earth
    Portal system. Students retain facts and analytical skills from the
    curriculum, especially material that is well represented by the
    Earth Portal interface that is difficult to represent in traditional
    mediums.