Technical description

(a) (b) (c) (d) (e) (f) Figure 6-13 The sign set that defines the language elements

Programming involves placing cubes on the programming mat in a linear sequence and this row is then interpreted from left to right. Figure 6-12 (c) is a photograph of a program that instructs the car to turn to the right, then move forward, move backward, and finally turn to the left. Figure 6-14 illustrates a program (a) with its TURTLE TALK equivalent (b) and the result (c) when the program is executed.

FORWARD RIGHT FORWARD RIGHT FORWARD RIGHT FORWARD

(a) (b) (c) Figure 6-14 A program, its TURTLE TALK equivalent, and execution results

Based on Smith (2009c)

6.3.2 Technical description

Cubes have soft foam sides and each contains between one and three magnets that are fixed along a diagonal line at the base (Figure 6-15a). The magnet configuration uniquely identifies the cube’s function to the electronic circuit and the sign (Figure 6-13) on the top serves to identify the function to the user.

(a) (b) (c) Figure 6-15 Foam cube, active square under construction, and toy car

The programming mat is a combination of active and passive squares where the passive squares serve as aesthetic and structural elements. Active squares (Figure 6-15b) each contain three magnetic switches that are sandwiched between two foam squares. Electronic circuitry can identify the cube based on the magnet arrangement inside the cube. This circuitry is also connected to a Lego RCX “brick” (Knudsen 1999).

The system interprets the line of squares from left to right and transmits one of six signals to the car (Figure 6-15c) corresponding to the cubes on the squares. The six signals represent each of the six language elements. Software executing in the car receives the signal and activates the electric motors and loudspeaker in response. The car then either adjusts its position, orientation, or plays a musical tune as is appropriate for the message received.

6.3.3 Evaluation

Formal evaluations provided insight to how well the artefact served as a tangible programming environment. The evaluations were integrated with workshops held at ScienceUnlimited (n.d.), SciFest Africa (n.d.), and TekkiKids (Marais et al. 2007): ScienceUnlimited in Pretoria and the Grahamstown based SciFest Africa are regional science fairs targeting the youth. TekkiKids was a multiyear research project that studied children’s interaction with technology through workshops in our laboratory and at a local school. Appendix F shows the workshop invitation extended to children at the SciFest Africa workshops in 2008.

6.3.3.1 Evaluation design

Workshop participants were school-going children, of mixed gender, mixed ethnicity, and undetermined social class. The workshops held at our laboratory and the school were part of a separate 24-month long research project conducted in collaboration with 10 to 13 year old participants. This research involved 36 children with six participants from each of four schools and 12 children from a fifth school. The participants from the four schools visited our laboratories twice a month, being two schools per visit. Interaction with the participants of the fifth school was on the

school premises. Workshops at the science events were attended by groups ranging in size of between two and 20 children and aged four to 17 years.

At the start of each science festivals workshop the research assistants solicited written consent from the parents and guardians who were legally responsible for the children. The same was done for the participants who were involved in our 24-month research project. The solicitation served to inform the parents, guardians, and participants of their rights. Appended E is an example of the consent form. The collected data included completed questionnaires, video recordings, and photographs.

The video recordings and photographs informed our evaluation analyses.

I introduced the participants to the programming environment and explained how the artefacts should be selected and positioned on the programming mats. The artefact components are the toy car, cubes, programming mat, and the execution mat. The functionality of each cube type was explained and demonstrated using the car.

User responses were elicited during evaluation sessions using two questionnaires. The questions are included in this thesis as Appendix G and Appendix H. The first questionnaire (Appendix G) is associated with the workshops conducted in our laboratory. The second questionnaire (Appendix H) supported the workshops conducted at the two science festivals. At the onset of a workshop, the participants completed Appendix G (Section A) and Part 1 of Appendix H. Section C of Appendix G and the third part of Appendix H solicit design inputs on sign language element representation.

Appendix G (Section B) and the second part of Appendix H were completed at the end of each workshop. Approximately 15 minutes were allocated to this activity.

Two primary activities formed the basis of evaluation workshops. First, the participants had to solve two challenges using the artefact. For the second activity, the children suggested alternative language element representations. The following paragraphs elaborate on these activities.

The two challenges required the participants to design and construct programs to guide the car to two rewards along a fixed route. The rewards are marked “Target object #1” and “Target object #2”

in Figure 6-16 (a) and Figure 6-16 (b), respectively. These targets were toys for the participant to keep. The toy served as both a concrete programming objective and a token of our appreciation for participating. The two challenges differed in the way that the car moved. For the first challenge, the only requirement was for the car to reach both targets. For the second challenge, the car had to reach Target object #2 by reversing. Figure 6-16 (c) and Figure 6-16 (d) illustrate two solutions to these challenges. Participants were encouraged to design solutions using printed copies of cube

signs called programming aids. Programming aids are printed copies of the sign set (Figure 6-13) and Figure 6-16 (a) shows them in use.

The programming activity went as follows: First, a participant was given a set of programming aids while at the same time I placed all the available programing cubes close to the programming mat and in no particular order. The child then placed the aids on the floor in the sequence (Figure 6-17a) that she envisaged would solve the challenge. I then helped her mentally execute each instruction in the compilation to validate the program against the set objective. When the participant was satisfied with the program design, she copied the design onto the programming mat by placing (Figure 6-17b) appropriate cubes onto corresponding active squares. The system was then activated and the car’s motions closely observed.

Target object # 1 Target object # 2 Toy car

Programming aids Programming cubes

Programming mat

(a)

(b)

(c)

(d)

Pathway

Target object

#1 Target

object

#2

Start position

Figure 6-16 The physical configuration, the challenge, and two solutions

Based on Smith (2009c)

(a) (b) (c) (d) Figure 6-17 Program design, construction, and debugging activities

Program debugging was done while the program ran. As the program executed, the user was encouraged to point (Figure 6-17c) at the cube being interpreted and simultaneously check if the car’s movement corresponded to the cube sign. A research assistant placed a smiling face icon on top of the cube (Figure 6-17d) when the car behaved as expected. When the execution did not correspond to the user’s intentions the discrepancy was resolved by inspecting the cube sequence and comparing the sequence to the car movements. The program was then modified, the car repositioned to the start of the route and the system reactivated. The debugging process was repeated until the car behaved as envisaged.

Once all the children have had an opportunity to construct and execute their programs they were asked to suggest alternative signs. They were requested to draw pictures (without text) to illustrate the following car motions: “Move forwards and keep on going”, “move forward and stop”, “turn right and stop”, and “turn right and keep on going”. Copies of the activity worksheets are in Appendix G (Section C) and Part 3 of Appendix H.

6.3.3.2 Evaluation results

Figure 6-18 and Figure 6-19 show some of the participants’ suggestions. The diversity in the suggestions supported my emerging thinking that users can design their own signs. Three design themes emerged. First, abstract signs such as a dot or vertical bar are at times used to indicate a stopping action (Figure 6-19c and d). Other abstract signs include dotted lines and multiple parallel lines to indicate that the car continues its current motion (Figure 6-18b and c). Second, concrete signs as found on the road side or tarmac, and hand signals indicate the intended action (Figure 6-18e and Figure 6-19a,b,e,f and g). Finally, a combination of abstract concepts and concrete objects were suggested and this is exemplified in the sketch (Figure 6-18a) as a car that changes shape as it passes through an intersection.

6.3.4 Discussion

Workshop observations established that individuals are able to conceptualise and express signs that represent car actions. A significant number of the suggested signs are similar to those already

incorporated into my artefact. The following may help explain this phenomenon: First, the participants were not motivated to generate original suggestions. Second, the participants did not understand the task and opted to imitate my signs.

The program element signs in this iteration are an improvement over those used in the first iteration. Substituting the acrylic programming mat and cubes with foam material was another refinement that yielded positive results.

(a) (b) (c) (d) (e) (f) (g) (h) (i) Figure 6-18 “Turn-and-go” signs

(a) (b) (c) (d) (e) (f) (g) Figure 6-19 “Turn-and-stop” signs