Archive for February, 2009

Physics Textbook 2.0

February 27th, 2009 No comments
Online Physics Flexbook

Online Physics Flexbook (click to expand)

Imagine a textbook that you can download, is open-source, is up to date with the latest information and you can comment on? Well, it exists. It’s called a “Flexbook” and today the state of Virginia released a Physics Flexbook online for a 2 week public review.

The 11 chapter online textbook contains a chapter devoted to teaching physics with modeling and simulation. It uses three Learning Labs developed with STELLA and allows students to interact with them using the free isee Player.

We got involved with the Physics Flexbook project last fall when we met the director of the program, Jim Batterson, at the MODSIM Conference in Virginia. He told us about a “wiki-style” online physics textbook that allowed teachers and scientists to collaboratively develop the content. The content would be free for anyone to use, share and adapt and contain the latest scientific information.

We thought this sounded like a fantastic idea and pledged our support for a chapter of the book that incorporates modeling and simulation to teach physics. Our friend Mark Clemente wrote the chapter and we setup a web page to host the STELLA models and allow easy access to the isee Player to interact with the models.

Earlier this week, Joanne and I were back in Virginia for the VSTE 2009 Conference (Virginia Society for Technology in Education). We attended Jim Batterson’s session on the Physics Flexbook where we got the full story on the inception and development of Virginia’s first open-source, online textbook. The session was very inspiring.

Jim Batterson is a retired NASA Engineer, former physics teacher and school board member. While Jim was at NASA he was chosen to direct a review of Virginia’s Standards of Learning (SOL) in science education. The goal was to come up with recommendations for the state on how to better meet the needs of the 21st century workforce.

Read more…

Setting Number of Points in a Graphical Function

February 25th, 2009 No comments

One of the questions I am sometimes asked is, “If I need a specific x-value to appear in my graphical function, how do I determine the number of points required to include that exact point?”  This arises because in a graphical function, the -axis is divided into fixed intervals; the user is only allowed to specify x-min, x-max, and the number of data points.  [If you really need a graphical function with arbitrary (x, y) points, use the LOOKUPXY() built-in function available in version 9.1.2.]

For the following discussion, the range on the x-axis will be needed:

range = x_max – x_min

In all of the examples below, x_min = 3.000 and x_max = 7.000, so the range = 7 – 3 = 4.

For integer values, here is a simple formula that always works:

# of data points = range + 1                                                                                  (1)

For example (using the range above), if the number 6 (an integer) must appear as a point on the x-axis, 4 + 1 = 5 points will be needed.  This divides the ­x-axis into the points 3.0, 4.0, 5.0, 6.0, and 7.0.

Fractional values, however, are more difficult.  In general, if you can isolate the fractional part (and this evenly divides the range), the maximum number of points needed is given by this formula:

Read more…

Welcome to the isee Blog

February 18th, 2009 21 comments

The isee systems BlogWelcome to the isee systems blog, “Making Connections”.  We hope you find it a practical resource for learning more about Systems Thinking, applying it to real-world situations, and using our software and training materials.

While we don’t have a set schedule, we post to the blog often. You can automatically get the updates by subscribing  via email  or using a news reader such as Google Reader, NewsGator or FeedDemon.

Most importantly, we want to hear from you. Please give us your feedback, post your comments, and keep us in the loop on what you’re doing and thinking!

Categories: News & Announcements Tags:

A Better Chained Slider

February 18th, 2009 No comments
Chained slider in iThink 9.1.2

Chained slider in iThink 9.1.2

The chained slider has always been a useful interface object in iThink and STELLA for allocating 100% of something to different variables within a model.  For example, you may want to build a dashboard where someone could play around with allocating funds to various programs within the Obama Administration’s economic stimulus package.

In iThink and STELLA version 9.1.2, we decided to improve the behavior of the chained slider in response to feedback we’ve received from customers.  We also wanted to nail down the behavior before we added support for it in models published to the web with isee NetSim.

Read more…

New ARRAYRANK Builtin Sorts Array Values

February 17th, 2009 4 comments

Version 9.1.2 will introduce the ARRAYRANK feature.  Here is a preview of its capabilities.

The ARRAYRANK built-in can be very powerful for some applications.  It allows you to order the values in an array from smallest to largest or vice-versa.  In this sense, it expands upon what ARRAYMINIDX (find the index of the smallest value) and ARRAYMAXIDX (find the index of the largest value) already do.

To introduce ARRAYRANK, let’s look at a simple model that uses it.  In this model, we explore the efficacy of applying tiered commissions for salespeople in an effort to encourage them to sell more.  Each tier is designed as a reward so the top seller in any given week gets the highest percentage, while those who do not perform will get the lowest.  The tiers are:

Top seller:                    20%
2nd best seller:            15%
3rd best seller:             10%
Everyone else:               5%

Note that the non-tiered system gave everyone 10%.  The model is very simple:


Read more…

VSTE 2009 Presentation

February 16th, 2009 No comments

vtselogoI will be presenting a session along with Mark Clemente next week (February 23rd, 2009) at the VSTE 2009 Conference.  The session is called “Practical Applications of Systems Dynamics and STELLA in the High School Setting“.  If you are attending the conference, you can come by Meeting Suite 5A on Monday at 8:30AM to check out the presentation.  We’ll be camped out in the suite for the day chatting with folks and demonstrating STELLA as well.

Last September, Joanne and I attended the Modsim 2008 Conference in Virginia Beach and met Mark.  Mark is a high school chemistry teacher and is currently an Educator-in-Residence at the National Institute of Aerospace.  He is a big part of the Hampton Roads Modeling and Simulation Initiative, which is a group of folks from the education system, government, local businesses and industry that are promoting the use of Modeling and Simulation to create a workforce for the 21st Century.

We’ve been happy to support Mark and the MODSIM initiative this year in their use of STELLA in High School. The presentation will cover how Systems Thinking, STELLA and dynamic modeling can be applied to High School curriculum.  We’ll be handing out a CD with tons of sample models, cirriculum and a 30-day workshop version of STELLA

Online Learning Labs Explore Systems Problems

February 12th, 2009 2 comments

If you’ve been connecting with folks at isee systems over the years, chances are you’ve read or learned something from Chris Soderquist. Chris is President of Pontifex Consulting and one of isee’s trusted consulting and training partners.

Chris SoderquistBefore branching out on his own, Chris worked for isee as a lead consultant, trainer, and learning environment developer. He co-developed the interactive teaching tool Systems Thinking: Taking the Next Step and has used our software to generate insight and understanding in others for many years. He is a real Systems Thinker and an excellent teacher. We think he is so good at teaching this systems stuff, we rely on him to facilitate our online training and to help us out at conferences and workshops.

Chris likes to tackle timely issues with Systems Thinking and is interested in how sharing models and videos online can help frame the discussion around them. Last year’s spike in fuel prices and public concern about future oil reserves inspired Chris to create a YouTube video and online Learning Labs to explore the supply and demand dynamics of the oil market.

YouTube video: “How long will oil last?”

Online Learning Labs

The following learning labs were developed with iThink and then published to the web using isee NetSim

How much oil is left?

Oil market dynamics

What do you think?

Chris is leading the effort to define an online Learning Lab format. We’d love to hear your reactions. Are there other topics you think this approach would be good for?

Dynamic Modeling Workshop in Cambridge, MA

February 11th, 2009 No comments
Steve Peterson coaches workshop attendees

Steve Peterson coaches workshop attendees

Our next workshop Introduction to Dynamic Modeling with STELLA and iThink will be held at the Royal Sonesta Hotel Boston in Cambridge, MA on March 24-26th. 

One of the benefits of attending the workshop is access to our consulting partners from Lexidyne LLC who bring a ton of real-world practical experience to class.  Come with a real modeling  project in hand and they’ll coach you through the process of conceptualizing and creating a dynamic model with STELLA or iThink.

Due to the hands-on nature of the workshop, class sizes are limited.   Please give us a call at (603) 448-4990 or send an email to to check on availability. 

We look forward to seeing you in Cambridge!

Categories: Training Tags: ,