User Interaction in Computer-based learning the bandwidth problem

Communication channels computer to learner – multi-media output devices focus on screen display learner to computer – input devices focus on mouse and keyboard

Screen display formats: text, image, animation issues: representation, focus of attention central concept: artifact of learning a minimal presentation unit which the learner must attend, perceive and interpret independently

Text artifact of learning content: vocabulary and style medium: font, size, colour, formatting constraints of medium: sentence and paragraph length, line length, page capacity focus of attention: linear along text control of attention: learner – text persists constraint of medium: identifying starting point(s)

Learning from text linear sequence of symbols (words +/-) focus of attention follows sequence but can be interrupted (look back or skip ahead; compare to audio)

Image artifact of learning representation: mapping content to image features focus of attention: displaying features so as to attract and guide attention of learner control of attention: learner – image persists

Image from content to representation zero dimensional artifacts (symbols) relational symbols ‘two and a half’ spatial dimensions

Image a one dimensional example different from text – order has meaning

attributes to map to: symbols: size, colour, shape planar dimensions: vertical position, horizontal position virtual third ‘half’ dimension: relative size, obscuring

attributes to map to: extensions to several diagrams layering – several diagrams with corresponding vertical and horizontal positions small multiples – sequences add more dimensions examples from Tufte

images: attention don’t distract – everything has meaning accompanying text explanation starting point colour, moderate complexity and ‘solidity’ attract the eye cultural biases for the ‘begin text’ position guiding path flow symbols near repetition