The Learning Design Sequence is presented as follows.

WHAT ARE THE STUDENTS REQUIRED TO DO?
SEQUENCE OF ACTIVITIES/TASKS?

The students are required to observe a physical phenomenon, attempt to represent the phenomenon in terms of structures and processes at the non-visible level, compare their representations with those of their peers and then with a well-accepted representation, discuss and compare their misconceptions with others and modify their representation of the physical phenomenon.

The complete sequence of the activities is critical in that the learner should make a commitment to a mental model of the phenomenon before comparing with a well-accepted version.

CRITICAL ACTIVITIES UNDERPINNING THE DESIGN

The critical activity is the student representing their model, and criticising this and those of other students with peers, before seeing a scientifically acceptable model. This is the most effective way to focus student attention explicitly on the key features, and identify misconceptions (if any). If sophisticated software were available, this could be achieved via pre-programmed feedback for common misconceptions. This activity should stress a high level of attention to detail. It is in the analysis of the detail that students can identify their misconceptions.

The final task in applying their refined model, once misconceptions are addressed, is also critical in order to reinforce the generality of the key features. The less time-intensive protocol of simply presenting a well-accepted representation, with explanation focussing on the key features, could also suffice in situations where students were already aware of the features.

SIGNIFICANCE/IMPORTANCE OF ACTIVITIES AND SEQUENCE

Science involves interpreting visible changes at the concrete observable level (e.g. muscles contracting, light from electric filaments) in terms of changes in structure and processes at the non-visible level (cells, atoms, energy). These changes are then represented at an abstract symbolic level in two ways: qualitatively, using specialised notation, terminology, and symbolism; and quantitatively, using mathematics (equations and graphs).

The need to be able to move between these three ‘thinking levels’, is a major problem for students learning science. This learning design explicitly encourages students to learn new science concepts by thinking and communicating about them at these three levels.
There is convincing evidence that most student difficulties and misconceptions in at least one science, chemistry, stem from inadequate or inaccurate models of the non-visible (molecular) world.

The most effective phenomena used in the learning design are those that create a cognitive conflict with an inadequate mental model held by a student, creating dissatisfaction with their current view. The time and effort taken to allow students to consider their prior views (Activities 2 & 3), and reflect on discrepancies between key features in their representation and the acceptable representation (Activities 5 & 6), are worthwhile according to this model.

WHAT RESOURCES ARE NEEDED?

The resources need to include a well-produced media element to demonstrate the actual physical phenomenon.

Background content should be provided regarding the non-visible level structure and processes involved in the physical phenomenon (i.e., accurate conventions for describing/understanding the symbolism or building blocks of the non-visual representation).

An audio explanation of the representation should also be available.

ESSENTIAL AND OPTIONAL RESOURCES

All of the resources are essential, with the exception of the background content about the non-visible structure and processes of the physical phenomenon. This content could be accessible to students in other ways, e.g. text books, previous subjects, etc.

WHAT KIND OF SUPPORT IS NEEDED?

The learner supports consist of:

• an introduction to the concept being investigated at the observable level;
• a tool to facilitate the learner's representation of the phenomenon as their mental model;
• feedback on the learner's representation; and
• a discussion space for a small group of learners to compare and contrast their representations and that of the well-accepted representation.

Support Element 1: Instructions on recording observations and background content.

The sequence begins with background content and/or a demonstration of a physical phenomenon, preferably in a live demonstration, or if this is not appropriate, using digital or analogue video. A simple example is the stretching of plastic Gladwrap® to tearing point. The exercise is to list all the significant observations, and this is not necessarily a trivial activity.

Support Element 2: Digital representation tool with acceptable conventions for representing the non-visible level in a drawing.

Instructions for students related to the drawing activity and thus, using the digital representation tool should include information about standard conventions of representation. Students should be expected to use standard conventions (e.g. molecular structure or vectors) in their describe/draw activity. Where no standard exists the student should be expected to develop their own convention and clearly indicate this through a symbol key.

Support Element 3: Feedback on student representation to enable focusing on key features.

Non-visible representations can be complicated so feedback is needed to focus student attention on clearly communicating the key features necessary to explain the observations of the phenomenon. Feedback should be provided from both peers and instructor.

Support Element 4: Focus on key features of acceptable representation.

The acceptable representation should be shown three times:

• First, without commentary, with students encouraged to look for the key features without assistance.
• Second, in segments, each with narration by the instructor drawing attention to the important key features.
• Third, in its entirety, with full narration.

If students are focused on comparing features in their representation with those in this representation, the impact is likely to be greater. However, it is essential for all the key features to be identified explicitly. Repeat viewing is advisable, but this could be left to the other support resources (Resource 6) for another time.

Support Element 5: Discussion Space.

Students often do not realise they have misconceptions, or have communicated misconceptions, in their drawings, unless these are pointed out. Peer criticism is useful for this purpose.

Students need to be encouraged to relate the three thinking levels in order to make sense of what they see in terms of what is happening at the observable level, and interpret the conventional scientific symbolism accordingly.

We have found that students need a physical 'memory' of the learning experience in the form of some kind of handout.

Subsequent opportunities must be provided for students to communicate their models of the non-visible world in lab reports and tests. If students do not think they will be assessed on these skills, they will not think they are worth the investment of time and cognitive effort.

WHAT ARE THE CRITICAL FORMS OF SUPPORT

The supports are all essential.

WHAT IS THE SIGNIFICANCE OF THE SUPPORT STRATEGIES?

In our view, the sequence should take students carefully through a mental journey requiring active thinking:

• from concrete to abstract levels (Support Elements 1 – 5);
• with focus on identifying key features of the non-visible level (Support Elements 4);
• identifying misconceptions, if any (Support Element 5), and application of visualisation skills to new chemical systems (Support Element 7).