Design Guideline 2: Dynamic Figures
Interactivity
Allow as much interactivity as possible in your dynamic figure. As a rule of thumb, all visible objects should be movable or changeable in some way. Your dynamic figure should provide plenty of freedom to explore the relations of its mathematical objects and discover mathematical concepts.
Easy-to-use
Try to make your dynamic figure as easy to use as possible. If an object can be moved or changed, try to make this obvious, e.g. all movable points could be red or larger in size. If you don't want objects to be changed, fix them (e.g. text, functions or slider positions) so they cannot be moved accidentally.
Note: If your students are likely to use a tablet or other touch screen, you need to adapt your dynamic figure accordingly (e.g. large points).
Size matters
Your dynamic figure should be large enough to allow all intended manipulations, but small enough to fit on one screen and still leave sufficient space for explanations and questions on the surrounding web page.
Note: Think about the screen size of device (e.g. notebook, tablet, phone) your students are most likely to use in order to work with the Dynamic Worksheet and adapt it accordingly. We recommend to try out the Worksheet on the same type of device prior to giving it to your students.
Use dynamic text
Dynamic text, like the length of a changeable segment, should be placed close to the corresponding object in your applet.
Avoid static text
Too much text can easily clutter your interactive applet. Instead, place static text like explanations or questions on the web page that includes your dynamic figure.
First appearance
When a dynamic worksheet is opened you should be able to read all labels and important information. For example, a point label should not be crossed by a line.
Try It yourself...
Task
Move point C along the semicircle. Can you come up with an assumption about the angles in this triangle? Check your assumption for different triangles by moving points A and B.