Logo Nanoworlds

Logo nanoworlds are small educational environments for Logo programming that focus on the mediation of intuitive models of informatics concepts. These are coherent Gestalt-like mental concepts, which are based on experience and which are subjectively certain (Fischbein 1987). Typical features of Logo nanoworlds are Visualisation of activity defined by a Logo programme Only a few Logo syntax elements are applied in each nanoworld Simple ad hoc understandable interactive elements Focus on certain intuitive models in each nanoworld Diversity of different intuitions in different nanoworlds Explication gaps High speed: a visit to a nanoworld takes just a couple of minutes Two prototype nanoworlds are presented, which both adopt a delegation model for procedure calls. In Turtles on the Beach the player constructs (possibly recursive) procedures that produce graphical patterns. The editing is done by manipulating “puzzle pieces” with code fragments on the screen. In contrast to conventional Logo Turtle environments the programme is executed by a team of Turtles. Each Turtle on the screen is attached to one procedure call. This model is supposed to facilitate the comprehension of recursive programmes. The second example is called Turtles in the Printery and is about recursive procedures containing print statements. Figure 1. Screenshots from the nanoworlds "Turtles on the Beach" and "Turtles in the Printery" Visiting a nanoworld is comparable to exploring an exhibit in a scientific museum or an art gallery. Classroom activities around nanoworlds include observing details of programme visualizations, comparing different intuitive models, bridging explication gaps and finding connections between visual representations and programming constructs.