Hardware Suggestions

In the process of building Roger’s Math Whiteboard I, (Roger Frybarger), have experimented with many various types of touchscreen hardware in an effort to determine what low-priced options might be appropriate for use in math classrooms. This was also necessary to ensure that my whiteboard program was compatible with such hardware. Anyhow, I thought it might be helpful to share what I have learned with the rest of the world so that anyone looking to equip a bunch of classrooms or otherwise do math on a touch/pen device can have a better idea of what to look for. Here is a summary of what I found:

  •      Overall, there is no standardization regarding how to handle input from various different devices. for example, touch input is handled differently on a capacitive touch screen than on a restive one. Not only that, some operating systems remove the mouse pointer when receiving pen/touch input, while others allow you to move the pointer around under your finger/pen. In some ways the lack of standardization makes sense because some touchscreens are capable of recognizing multiple touches and some are not. In other ways, this lack of standardization can make life difficult. In my case I had to handle all types of input. Thus, I had to solve this problem by finding the lowest common denominator between all the various devices. This lowest common denominator ended up being the ability to track a single mouse/pen/finger across the screen. Thus, I ended up ignoring many features of the other various devices because they weren’t standardized.
  •      I found that a standard capacitive touchscreen could be used to draw with, but was prone to interpreting my palm as a finger. Because of this, a standard capacitive touchscreen can have serious ergonomic issues because the presenter can’t easily rest their hand on it. This is especially true for laptops that don’t allow the touchscreen to be folded into a flat tablet-like configuration. Reaching out over a keyboard to draw on a touchscreen is sure to result in a tired arm. For those reasons, I would actually prefer having only pen input and no touch input, contrary to today’s trends.
  •      Precision is quite important for drawing math on a touchscreen. Math syntax often involves lots of carefully placed symbols, and an inaccurate touchscreen can waste the presenter’s time with endless corrections. I found that the level of precision is far better with a Wacom/Penabled laptop than with a standard touchscreen, which makes these devices far easier to use. I also found that my finger, (or a capacitive stylus) would hide the point where I was actually creating the line, which tended to further decrease accuracy. I experimented with various capacitive styli in an attempt to fix this problem, with only mixed results. A resistive touchscreen with a simple dull-point plastic stick can be more accurate, but still isn’t as good as a penabled laptop because these touchscreens usually lack the mouse hover feature, and can still interpret palms as fingers.
  •      I have also experimented with a used/surplus point of sale touchscreen which used a surface acoustic wave technology. On the whole, I didn’t find it to be all that useful. Unfortunately, it didn’t seem to be made with a high level of accuracy in mind. This means that a line drawn at a diagonal usually ended up looking more like a set of stair steps than a straight diagonal line.
  •      I found that USB drawing tablets such as the Huion h420 were a viable addition for computers that were otherwise operational, but lacked touch input. The only problem was getting accustomed to drawing on the tablet while looking at the screen. Also, for presenting math content, I found that the pressure sensitivity feature wasn’t really particularly useful, since once again, it wasn’t standardized. I found that just being able to move the mouse around on the screen was sufficient. Perhaps if one also intends to do art on the same machine it might be useful, but for math, I found it to be more of a nuisance than a useful feature.
  •      Personally, my favorite device is the Lenovo ThinkPad X200 Tablet with the resistive/capacitive touch screen panel turned off. I find the pen to be entirely sufficient, and work in an completely intuitive way. It will hover the mouse over a particular point if I hold the pen above that point, and will fire a left-click when I touch the screen. The pen also has a button for right-clicking if needed. As for an Operating System, I run a customized version of Xubuntu on this machine since I found that it would still show the mouse pointer when using the pen. At the same time, I also found the Huion h420 to be a useful drawing tablet for use on my desktop. While it definitely feels like thin plastic, and took some work in order to play nicely with my dual-screen setup, it is a surprisingly useful tool given its cost.

Overall, I wish that device manufactures would pay a little more attention to the needs of presenters. Most of them seem to assume that everyone will be able to watch the presenter drawing on the device. Unfortunately, this is just not the case, and this inaccurate assumption often leaves students in the dark to a certain degree. I hope in the future they will make it easier to point at things and have everyone see clearly what is being explained. 

For those looking to equip math classrooms or who are otherwise in the market for this sort of hardware, look for a folding laptop with a pen. In my experience, these tend to be the best. In a classroom setting, consider attaching the pen and computer to the desk via locks and/or a string for the pen. This will help avoid lost pens and stolen laptops. Also look for the ability to rest one’s palm on the touchscreen while writing. Furthermore, the ability to hover the mouse with the pen without clicking is also very important. I would recommend staying away from capacitive touchscreens and used point of sale touchscreens since they typically lack the accuracy that is needed. However, if a penabled laptop comes with such a touchscreen, these can usually be turned off. If you already have a desktop computer, monitor and a projector, (if you need a projector), I would recommend looking into an external USB drawing tablet. These can be obtained at a very reasonable price-point for the individual, and could be useful in the classroom if they can be secured to something. Here again, the pen should probably be tied to the desk to ensure that it doesn’t get lost. 

Some of you may notice that I have not discussed interactive whiteboards or Smart Boards. This is because I have not found these devices to be particularly helpful to the math teacher, or to the student trying to learn the material. My reasoning is as follows:

  • First off, these devices are quite expensive, which further strains already tight school budgets.
  • Second, the general idea behind an interactive whiteboard is to be interactive. This typically involves the students being able to walk up and write on the whiteboard along with the teacher, which can be impractical at larger class sizes.
  • Third, the presenter must typically turn their back to the audience in order to draw on the whiteboard. This results in a lot of unnecessary movement and is not an ideal arrangement. 

In sum, there may be some cases where an interactive whiteboard is a helpful tool, such as in small classes where student collaboration is the intended goal. However in most cases, I have found that they provide no advantage over a standard projector connected to a laptop with a pen. I have found that it is better to have a laptop computer with a pen on the instructor’s podium and have that screen projected onto a larger screen by a standard projector. This allows the instructor to face the students while also writing on the screen. This is not only a better ergonomic arrangement, it is also less expensive and results in easier communication between the instructor and the audience. If your school has already invested in interactive whiteboards, then they are certainly worth using, but if you are starting from a clean slate, I would argue that you can get a better system for less money by using laptop computers with pens.

Last updated Nov 10, 2017
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