QUALITATIVE QUALITATIVE MODELING IN MODELING IN EDUCATIONEDUCATIONBert Bredweg and Ken ForbusBert Bredweg and Ken Forbus

Yeşim İmamoğluYeşim İmamoğlu

Computers and Education

Using educational software Supports constructivism in education Allows multiple representations and

interaction Serves to individual differences

Qualitative Reasoning and Education

Qualitative reasoning is valuable for education because:

Uses of conceptual knowledgeWhat happens, when does it happen, what

effects it, what does it effect? Provides grounding and framework for

quantitative and traditional mathematical models

Recent Applications

Teachable Agents project (Vanderbilt University, Biswas et al. 2001)Betty’s Brain-qualitative mathematics

ALI (D’Sauza et al. 2001)Based on qualitative process theoryDomain independent-can be attached to any

quantitative simulation

Recent Applications

Application of qualitative process theory in chemistry classes (Syedd, Pang and Sharifuddin, 2002)Qualitative model is used alongside

classroom experiment to determine optimal use of substances

Aspects of modeling that existing visual languages do not address The importance of broadly applicable

principles and processes Understanding when a model is relevant Qualitative understanding of behavior

VModel

Student friendly visual notation for qualitative process theory

Creates a software environment that helps students express their qualitative, conceptual models

VModel Visual notation is based on concept maps Nodes represent entities and properties of

entities Each node has a specified type such as

Thing, Multiple Thing, Substance or Process

Quantities are used to describe the continuous properties of entities

Links represent relationships, labels are drawn from a fixed set of relationships

VModel Small, fixed set of structural relationships

Touches, Contains, Part of...

Ordinal relationships Greater Than, Less Than, Equal To

‘Requires’ relationship links a process to the conditions that enable it

Casual relationships Increases, Decreases: direct influences (I+/I-) Influences, InfluencesOpposite: qualitative

proportionalities )/( QQ

VModel Two coaches:

Qualitative simulation to help the students see how well their model make predictions

Modeling equivalent of spelling and grammar checking

Three sources of feedback: Visual step-by-step animation of the simulation English summary of behavior predicted by the model Assessment of how well the model supports the

hypothesis

VModel

Model library: contains all the models that the students have created

Students can build their own domain theory

HOMER and VISIGARP

Allow learners to use a qualitative reasoning engine for running and inspecting simulations

They work on top of the domain independent qualitative reasoning engine GARP

Use diagrammatic reprsentations for buliding and inspecting qualitative models and simulations

Model Building with HOMER Organized set of builders and tools Builders:

Capture knowledge and use diagrammatic representations

Used for creating building blocks (entitiy hierarchy, quantities, quantity spaces...)

Tools: Interactive dialogues for modifying the content of builders

Constructs: Model fragments and scenarios Assembled from building blocks

Model Building with HOMER Task:

Create a set of model fragments (stored in library) Specify one or more scenarios (structural description

of the system)

Model Building: Simulator uses the model fragments to predict the

behavior of the system defined in the selected scenario

For each of the specified scenarios, the simulator generates the intended behavior graph

HOMER Prevents learners from making syntatically incorrect models

The user interface restricts user actions based on Content Current selections in the builder that the user is

working on Investigates each user action with respect to

side-effectsNotifies the user Gives user the option either carry on with the action or cancel it

Problems encountered using HOMER

Homer was tested on two researchers and two

master students from a computer science

department Problems caused by poor use of the tool Problems caused by subjects not fully

understanding how to perform a task

(model building problems)

Model building problems Model scope:

Determining which features of the real-world sytem to include in the model

Model Structure: Determining what to put where in the model

Model Building Concepts: Understanding the meaning and difference between

the concepts provided by the tool Model Representations:

Knowing the concept, what to represent but not knowing how to represent it

VISIGARP

Provides a graphic interface to for running and inspecting qualitative simulations

Simulations might use models constructed by teachersdomain experts the learners (for example, by using HOMER)

VISIGARP

Visual container: All model ingredients belonging to a particular area are grouped into a single box

Ingredients relating aspects from different entities cross the border of the boxes

Usability of VISIGARP

Experiment was conducted to 30 first year university (psychology) students

Pretests and posttests were conducted on domain knowledge and icon language of VISIGARP

Treatment: Prediction exercises using simulations

Subjects were asked to evaluate VISIGARP after treatment

Usability of VISIGARPResults indicate that:

There was significant difference between pre/post tests in domain knowledge

No significant difference between pre/post tests in icon language

Most icons were easy to learn: ≤, <, =, ≥, P+, P-, I+, I- A few icons were hard to understand: Q^, Q, V^, V (they

were not used much during simulation) VISIGARP did not always produce insighful graphs for comlex

models Attitude test revealed that subjects evalated the usefulness of

VISIGARP quite positively

Conclusion

Importance of conceptual knowledge in education

Reasoning about system behavior Two qualitative models: VModel and

HOMER/VISIGARP combination Both foster learning as a constructive process

Comments Experiments are done with subjects at the

university level Further adjustments may be needed if it is

going to be used in high-middle school level (more user friendly)

Suitable for the new curriculum in Turkey, but not easy to put into practice