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2018 IEEE Symposium on Visual Languages and Human-Centric Computing (VL/HCC) (2018)
Lisbon, Portugal
Oct. 1, 2018 to Oct. 4, 2018
ISSN: 1943-6092
ISBN: 978-1-5386-4236-8
pp: 57-64
Islam Almusaly , Oregon State University
Ronald Metoyer , University of Notre Dame
Carlos Jensen , Oregon State University
Block-based programming languages are used by millions of people around the world. Blockly is a popular JavaScript library for creating visual block programming editors. To input a block, users employ a drag-and-drop input style. However, there are some limitations to this input style. We introduce a custom soft keyboard to input Blockly programs. This keyboard allows inputting, changing or editing blocks with a single touch. We evaluated the keyboard users' speed, number of touches, and errors while inputting a Blockly program and compared its performance with the drag-and-drop method. Our keyboard reduces the input errors by 68.37% and the keystrokes by 47.97 %. Moreover, it increases the input speed by 71.26% when compared to the drag-and-drop. The keyboard users perceived it to be physically less demanding with less effort than the drag-and-drop method. Moreover, participants rated the drag-and-drop method to have a higher frustration level. The Blockly keyboard was the preferred input method.
Keyboards, Connectors, Programming, Visualization, Syntactics, Performance evaluation

I. Almusaly, R. Metoyer and C. Jensen, "Evaluation of A Visual Programming Keyboard on Touchscreen Devices," 2018 IEEE Symposium on Visual Languages and Human-Centric Computing (VL/HCC), Lisbon, Portugal, 2018, pp. 57-64.
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