Computer Science Teacher
Computer Science Teacher - Thoughts and Information from Alfred Thompson

November, 2008

  • Computer Science Teacher - Thoughts and Information from Alfred Thompson

    Top 10 Education People to Follow on Twitter


    This is a list of the people I know who are twittering about education (in general – not much CS education) and who I think are the people to follow if you are looking for people to follow on twitter about education. If you are looking for a very scientific and highly authoritative list of the top education people on Twitter that everyone should follow this isn’t it.

    The ideal list would include a systematic study of who is following who, who is replying to who, and take into account all the followers each person has. Twitter Grader does something like that and its ranking was one thing I took into account when I created this list. But my list is also highly subjective based on who I see talking and more importantly who I perceive as others taking seriously. If you went strictly by Twitter Grader this is not the list that would result. There are some high ranking Twitter people who just don’t twitter as much or engage in as many conversations. I see conversations as a real good thing in someone I am thinking about following.

    I follow all of these people and most of them follow most of the rest of the list. A couple follow me too. :-)

    So here is my list in no particular order. The first column is their Twitter user name with a link to their Twitter page. The second is their name in real life with a link to their blog if they have one. Lastly is the Bio they used on their Twitter page. This is a format and an idea inspired by the list Ten People All Twitter Beginners Should be Following by Mark Hayward wrote for the ProBlogger Blog Tips blog.

    Jump in and tell me who I should have put on it and who I should have left off. Tell me WHY though.

    chrislehmann  Chris Lehmann Principal of the Science Leadership Academy
    garystager Gary Stager
    teach42 Steve Dembo Online Community Manager, Discovery Education
    coolcatteacher Vicki Davis Teacher, blogger, technology geek, Mother
    jutecht Jeff Utecht   Education, Technology, Consultant, Presenter
    dwarlick Dave Warlick 30+ year educator, technologist, programmer, author, & public speaker
    wfryer Wesley Fryer I'm here for the learning revolution
    budtheteacher  Bud Hunt I'm learning.
    McLeod  Scott McLeod Director, CASTLE.
    jonbecker Jon Becker Assistant professor of educational leadership at Virginia Commonwealth University (VCU)

    If you want to follow me on Twitter I am at AlfredTwo.

    BTW if you are interested in education blogs take a look at this post by Scott McLeod who looks at recent changes in Technorati rankings of the to 50 education blogs.

  • Computer Science Teacher - Thoughts and Information from Alfred Thompson

    Fun With Formulas


    Last week I was in Denver for a large middle school STEM event. They had a large selection of workshops for well over 1,000 middle school girls. My co-worker Hilary Pike did three workshops while I took care of our booth. During a lull I had a chance to visit other booths and one of the booths I visited was by the American Council of Engineering Companies in Colorado. I picked up a bookmark that told about horsepower. Did you know that horsepower was based on James Watt finding that a work horse could lift a 1,000 pound weight 33 feet in 60 seconds? Neither did I. Well actually it is more complicated than that and there are actually a number of different ways to calculate horsepower. Visit Wikipedia at for some additional information and links.

    But for the time being let’s stick with this definition. If you want to figure out your own horse power you can do so by using your weight, and counting the steps you can climb in a minute. So if you are 100 pounds and climb 495 8-inch stairs in a minute that is one horsepower. The bookmark I picked up had this formula for figuring out how many steps one had to climb in in minute for one horsepower.

    33,000 ÷ your weight = (answer)
    (answer) x 1.5 = number of steps to climb

    My fist inclination since I love math but am not overly fond of doing division and multiplication by hand was “hey I can write a short program to do that!” So I did. I translated that formula to C# as:

                int iWeight = int.Parse(textBox1.Text);
                int ans = 33000 / iWeight;
                double  dSteps = ans * 1.5;

    That code takes a weight as string from a textbox and displays the number of steps to climb for one horsepower in a message box. In Visual Basic .NET it would be:

    Dim iWeight As Integer = Integer.Parse(textBox1.Text)
    Dim ans As Integer = 33000 / iWeight
    Dim dSteps As Double = ans * 1.5

    Well you could do this just as well with a calculator or a spreadsheet.


    So what kind of program is that? Pretty boring. So I started thinking about ways to make it more interesting. Perhaps a table? The very earliest computers were used to compute all sorts of tables. Of course back then computers took up whole rooms and so printing out tables was the way to go. But still I think there is some learning we can get from all this.

    First off what if you don’t have 495 steps to climb? If you have fewer steps to climb you are likely not to take a whole minute to climb them. The obvious answer is to build a formula that takes the number of stairs you climb, the time you take to climb them and your weight into account and tells you how much horsepower you have generated. Yeah, algebra! So that’s what I did.

    But you know it still seemed like building a table was a job for a spreadsheet. So to test my formula I built a spreadsheet. I put the number of steps in cell A1 and built a list of weights across the top and a list of seconds down the left side. By the way if you haven’t looked into Auto Fill in Excel you are missing a great shortcut.  I then created the formula (no I’m going to leave figuring that out to you. Ask a Math teacher for help in you need it.) I used absolute addressing so that I could then just copy cells to fill out the spread sheet. And lastly I added conditional formatting to make cells that were more then one horsepower red, one horsepower to .70 horsepower in green and less than .70 horsepower in yellow. The results looked like this for 60 steps.


    I think the coloring adds to the table. To me it makes things more clear at a glance. Using color in tables can be very helpful if not overdone.

    So I started with a computer program that really was a better fit for a spreadsheet. Back when I started with computers we didn’t have spreadsheet programs which is probably why my mind still starts with “write a program.” This is something of a reminder to me to think a bit more about the right tools for the job. In between I was reminded yet again that algebra skills can turn out to be very useful when you have one formula but really need another one. And of course I had to throw in conditionally formatting to remind myself and others that the sort of things one learns in programming (conditionals in this case) often leads to useful thinking for other applications.

    ACEC has a number of other interesting items – fun facts and activities - for students at their web site. Check it out.

    There is a lot to think about and learn about in engineering and a lot of it is fun!

  • Computer Science Teacher - Thoughts and Information from Alfred Thompson

    Computer Science for Middle School


    I spent yesterday at a large STEM event in Denver Colorado. Something like 1,500 middle school girls were brought to the Colorado Convention center for workshops and talks about science, technology and engineering. My colleague Hilary Pike conducted several workshops while I manned the booth we had in the exhibit area. While Hilary was working with students I was talking to teachers and parents who had brought the girls to the event. The common question was what resources are there for teaching computer science concepts to middle school students? I have a short list that I shared with people but it seemed like this was something that should be blogged about as well. If nothing else maybe it will help people using Internet search engines to find useful tools.

    Kinesthetic learning works well with middle school students if for no other reason that sitting still is not fun or easy for them. So the CS Unplugged materials should be very useful in this environment. I love these activities as they show the concepts without the need for computer hardware, special software or other expensive resources. And kids enjoy them. Since there is a story attached and an activity attached I think that students are more likely to remember what they are learning. As a bonus it really shows that computer science is more than just programming.

    For programming a couple of popular tools come to mind. Alice and Scratch are tools that use a drag and drop building block approach to programming. These tools allow students to learn about programming without syntax getting in the way. These tools are colorful and graphical. Alice uses a 3D environment while Scratch is 2D. Scratch is somewhat lighter in weight so tends to work better on older hardware than Alice. Both have versions for both Windows and Mac.

    Storytelling Alice was developed especially for middle school. It was built from Alice but is not 100% compatible. The storytelling features though have been tested as being very effective with middle school students and especially with girls. It is Windows only and doesn’t have quite the same support at regular Alice but it seems pretty stable.

    If you are “in to” BASIC or other traditional programming languages two resources that are available are Small Basic and a curriculum called “Code Rules” that uses Visual Basic. Small Basic is as simple to use development environment that uses a simplified version of BASIC. I wrote more about it here. Code Rules is a curriculum that was designed for high school students but its approach is very basic (no pun intended) and for some 7th and 8th graders I think it would work very well.  Both are obviously Windows only as they are from Microsoft. But they’re free.

    There are more as well. I have heard good things about Squeak for example. And there is a simple programming language for beginners called Leopard that I don’t know that much about but looks interesting. And Phrogram which used to be called Kids Programming language or KPL is being used in a lot of schools. For kids interested in games there is My Game Builder and Popfly about which I have written a lot.

    Edit: In the comments I was reminded of FIRST Lego League which is a great robotics program for middle school students.  It introduces a lot more than programming as they always tie the projects into other science areas.

    I think that many of the tools I have written about in posts tagged first programming experience would work with middle school students. Not all of them will work in every middle school of course. But most will at least be usable by students who really want to get their feet wet.

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