Running DynaLearn

How do I start a new model?
How do I start a new model in Learning Space 2?

Modelling

What is an attribute?
What is the difference between an attribute and a quantity?
What is a configuration?
What is a property?
What is a quantity?
What is the difference between an entity and a quantity?
How do I add a configuration?
How do I add a causal relationship?
How do I add value?
How do I use the same concept twice?
How do I use the same entity twice?
How do I use the same quantity twice?
All my quantities are given the same name, how can I change it?
I had added a relationship, but now it is suddenly gone.
How to add a positive / negative correlation to an existing configuration?
If I calculate a + or -, How do I relate a quantity to the outcome?
How do I change the direction of an equivalence relation (‘=’ relationship)?
Why is there sometimes both a correspondence and a ‘=’ relationship between two quantities?
How do I start a subtype hierarchy?
How do I create exogenous behavior?
How do I get to the screen where I can add entities and quantities in LS6?
If I create a quantity, I get a message that the quantity space is not allowed. But I do have selected a quantity space.
Why can I not add Influence?
Why are all my quantities gone?
I cannot click an I-relation, how is this possible?
What is a dead-end?
How to add an equivalence relation between two derivatives?

Simulation

Why do I not get a simulation at all?
Why do I get (much) fewer states than I expected?
Why do some quantities do not have a derivative in the value history?
[LS2] Why do I get a question mark in the simulation?
[LS2] What is the meaning of 3 value assignments (indicated by blue arrows)?
If I have a set a value and I run a simulation, can this value change?
I have two negative or two positive influences on the same quantity, and yet I get an indefinite simulation results. How can this be?
If I run a simulation in LS3, I get no states. Why?
I get a simulation with only one state, which is yellow.

Teachable Agent

How do I enable sound for my teachable agent?

Other

How do I unpack a zip file?
Why does the file not open after double-clicking on the file icon?
What is the use of a quantity if we do not run a simulation?
What can you do with the blue arrows that can be placed at the three black marks?
Is temperature or radiation a quantity?
How can I create a JPEG file from my file?
How can I make sure that, without giving a value for the radiation of the sun, I can let the simulation run in a loop?

Running DynaLearn

How do I start a new model?
In the “File” menu click on “Start new model”. You then can give the model a name on the left side of the window and choose the learning space on the right.

How do I start a new model in Learning Space 2?
Select “Basic causal” when creating a new model.

Modelling

What is an attribute?
An attribute is a property of an entity (or agent) that cannot increase or decrease.
⇒ Glossary: Attribute, Entity

What is the difference between an attribute and a quantity?
Attributes and quantities are properties of an entity (or agent). Quantities are properties that may increase, decrease or remain the same. An attribute can only take one value from a number of possible values. Temperature is an example of a quantity, it can increase, decrease or remain the same. The color of a thing is an example of an attribute, because color can not increase or decrease (although the color intensity, but that is again a quantity).
⇒ Glossary: Attribute, Quantity

What is a configuration?
Configurations are associations between two entities. Configurations can be divided into several categories:

  • Part/subpart relationship: “liver is_part_of human_body”.
  • Individual/definition: “appeltree28 is_a apple_tree.”
  • Species/Genus: “apple_tree is_of_type tree.”
  • Positional relationships: “appletree28 next_to peartree3.

⇒ Glossary: Configuration

What is a property?
There are two types of properties:

  • Attribute: a property of an entity that can not increase or decrease, for example “color”.
  • Quantity: a property of an entity that can increase or decrease, for example, ‘amount’ or ‘temperature’.

⇒ Glossary: Attribute, Quantity

What is a quantity?
A property of an entity that can increase, remain stable or decrease.
⇒ Glossary: Quantity

What is the difference between an entity and a quantity?
An entity and a quantity both represent a concept but have the following differences:

  1. A quantity may increase, remain constant or decrease. In other words, a quantity can be quantified. For an entity, this is not the case.
  2. Quantities are allocated to entities, while entities cannot be allocated to quantities.
  3. An entity has an individual right to exist. This means that an entity can exist independently of a quantity. A quantity, however, cannot exist independently of an entity (this follows from item 2).
  4. Causal relationships between quantities can be defined. Causal relationships between entities can not exist. Configurations can be created between entities, while this in turn is not possible between quantities.

We now give some examples of entities and quantities:

  • The concept ‘Sun’ can not be quantified in a meaningful way. We can not talk about the increase or decrease of the Sun
  • The concept of ‘temperature’ can be quantified in a meaningful way. Indeed, temperature may increase or decrease.
  • Sometimes we say in colloquial speech that something is increasing or decreasing, while it is strictly speaking not the case. When we say “Biofuel is increasing.” we mean that the number of biofuels. In terms of the modeling language ‘biofuel’ is an entity and ‘amount’ is a quantity belonging to that entity.

⇒ Glossary: Attribute, Entity, Attribute, Quantity

How do I add a configuration?

  • Select an entity.
  • Hold the ‘Shift’ key.
  • Select one another, second entity.
  • Release the ‘Shift button.
  • In the menu on the left side, a button becomes active with the tooltip “Add a configuration”.
  • Click this button to add a configuration.

How do I add a causal relationship?

  • Select a quantity.
  • Hold the ‘Shift’ key.
  • Select one another, second quantity.
  • Release the ‘Shift’ button.
  • In the menu on the left, two buttons become active: one with a plus sign and one with a minus sign.
  • Click on one of these buttons to add a causal relationship (positive or negative).

How do I add a value?
Values can only be assigned to quantity space of a quantity:

  • Select a value of the quantity space.
  • In the menu on the left, click on the button with the blue arrow

⇒ Glossary: Quantity, Quantity Space, Value Assignment

How do I use the same concept twice?
There are two types of concepts: entities and quantities.

How do I use the same entity twice?

  • Click ‘Settings’ > ‘show super types.’
  • Click the button on the left to add an entity.
  • In the dialog for adding an entity, you can now add a super type, in this case ‘Tree’.
  • You can add a name to the specific tree you are using, such as ‘tree1′.
  • You can then add a second tree by selecting the same super type in the dialogue and adding an other specific name such as ‘tree2′.

How do I use the same quantity twice?
You can use the same quantity, eg ‘temperature’ for various entities. You can add for example a temperature to a lake and to the atmosphere.

All my quantities are given the same name, how can I change it?
When you create a new quantity, click first on the top button on the left side: “Add quantity definition”, otherwise you only modify your existing quantity.

I had added a relationship, but now it is suddenly gone.
Pressing the space bar hides the elements connected to the selected element. To make them visible again you can right click and select “Expand All”.

How to add a positive / negative correlation to an existing configuration?
A configuration is a relationship between two entities. A positive/negative relationship is always a causal relationship. But a configuration is not a causal relationship. Causal relationships (positive and negative) can only be created between quantities.
⇒ Glossary: Configuration, Causal Dependencies, Quantity

If I calculate a + or -, How do I relate a quantity to the outcome?
The +/- bar represents a new value, the result of the calculation. This value can be put into relationship with another quantity. For example by an equality or inequality relationship.

To do this, select the calculation, press ‘Shift’ and the select another quantity. Now, the quantity can be equated to the result of the calculation with the ‘=’ relationship.
⇒ Glossary: Operator Relation, Quantity

How do I change the direction of an equivalence relation (‘=’ relationship)?
An equivalence is symmetric. This means that the direction of the arrow does not matter. (If A = B then B = A.)
⇒ Glossary: Inequality

Why is there sometimes both a correspondence and a ‘=’ relationship between two quantities?
A correspondence between quantities A and B says that when A has a certain value, B has the corresponding value.
A ‘=’ relationship can also work when a ‘>’ relationship is active: if A > C and B = A, then B > C.
⇒ Glossary: Inequality

How do I start a subtype hierarchy?
A subtype hierarchy is a hierarchy of entities.

  • In the upper menu bar, select the left icon (entity).
  • Click on the base type (Entity).
  • In the left toolbar click on “Add entity to hierarchy”.
  • Your new entity is a subtype of the root Entity.

⇒ Glossary: Subtype Hierarchy

How do I create exogenous behavior?
In the scenario, double click the quantity that you want to give exogenous behavior and select a type of behavior from the list “Exogenous”.

How do I get to the screen where I can add entities and quantities in LS6?
Unlike LS2-5, you can create multiple model fragments in LS6.
Before you can make your model, you will need to define one or more model fragments:

  • Click in the upper menu bar on “Open model fragments editor.”
  • Click on the type of model fragment that you want to create: static, process or agent.
  • Click “Add model fragment.”
  • You can adjust the new model fragment by double-click it.

If I create a quantity, I get a message that the quantity space is not allowed. But I do have selected a quantity space.
Select a quantity space from the list is not enough. Click the button above the selected quantity space to import it to the quantities allowed for this q-spaces.

Why can I not add an influence?
Influences can only be added in process model fragments, not in static model fragments.
⇒ Glossary: Influence, Model Fragment

Why are all my quantities gone?
If an entity or agent is yellow it means that quantities related to the entity or agent are hidden.
Right click > ‘expand’ makes these hidden quantities visible again.

I cannot click an I-relation, how is this possible?
I-relations, or “Influences”, can be added only in process fragments, but not in static fragments.
⇒ Glossary: Influence, Model Fragment

What is a dead-end?
A dead-end is a final state in which a quantity increases but not to the highest value. This dead-ends are generally not desirable as you expect an ever-increasing quantity that eventually will reach the highest value.

How to add an equivalence relation between two derivatives?
Select both derivatives (by clicking on the delta symbol). If you have selected the two, an equivalence can be added.

Simulation

When you have created a model you can test whether the modeled system behaves as you expect by setting the value of a few quantities and then clicking the ‘Simulate’ button in the upper menu-bar. The simulation calculates the values of the other quantities. Are these values as you’d expect? Then this is a indication that your system is valid.
⇒ Glossary: Derivative, Operator Relation

Why do I not get a simulation at all?
The simulation calculates the values propagated by causal relationships. This means that your model must have at least the following ingredients:

  1. Causal relationships between quantities.
  2. Values assigned to the quantities.

Only when these ingredients are present, the values can be calculated based on the causal relationships.
⇒ Glossary: Simulation

Why do I get (much) fewer states than I expected?
The state graph does not tell the whole story about the simulation. See for example, the value history for all states. Do all quantities have the expected values?
⇒ Glossary: State Graph

Why do some quantities do not have a derivative in the value history?
If a value history looks like in the picture below, this is often a sign that the scenario does not correspond to one or more of the model fragments. Scenario and model fragments have to align perfectly: the entities, quantities and configurations must be identical.

⇒ Glossary: Derivative, Value History

[LS2] Why do I get a question mark in the simulation?
This means that the simulation has inconsistent results. In other words, the simulation results calculated by the simulator violate some value assignments (values assigned by you). To solve this problem, some value assignments and/or some causal relationships have to be adjusted.
⇒ Glossary: Simulation

[LS2] What is the meaning of 3 value assignments (indicated by blue arrows)?
This means that it is not known what the value of the quantity is. It might increase, decrease or remain the same. This can happen when there are different, opposing effects on a quantity.

If I have a set a value and I run a simulation, can this value change?
No, the values you’ve set are not re-calculated.
⇒ Glossary: Simulation, Value Assignment

I have two negative or two positive influences on the same quantity, and yet I get an indefinite simulation results. How can this be?
The effect of an influence has two aspects: the preceding decrease or increase and the relation with the next quantity. For example a decreasing quantity with a negative effect on another quantity increases this quantity etc. In other words, ++=+, +-=-, – + =- and –=+.
⇒ Glossary: Influence, Simulation, Simulation Output

If I run a simulation in LS3, I get no states. Why?
The initial values you set must be consistent. I.e. if you set a certain quantity to increase and this quantity influences another quantity positively, you can not set this other quantity to remain the same.
⇒ Glossary: Scenario, Value Assignment

I get a simulation with only one state, which is yellow.
This is a partial simulation. If you click on the button with the brown state icon, the successor states will be calculated.

Teachable Agent

How do I enable sound for my teachable agent?
First, start the Mary TTS server. A windows open, do not close it. (Re)Start the DynaLearn software.

Other

How do I unpack a zip file?
Right click on the ZIP file and select “Extract All”.

Why does the file not open after double-clicking on the file icon?
The software does not register its file types. In order to open a file you first start the software and from there you can open the model files.

What is the use of a quantity if we do not run a simulation?
We do run a simulation, this is done by setting the values of a number of quantity derivatives. Then click the Simulate button on the left of the upper menu bar. The values for the other quantities will be calculated.

What can you do with the blue arrows that can be placed at the three black marks?
With the arrows you indicate whether a quantity increases, remains the same, or decreases. You set this for a few values that you know. Then you run a simulation to see what the effect is on the quantities that you do not know. See also ‘How do I add value?’

Is temperature or radiation a quantity?
Often it is. But strictly speaking it depends on how it is used. If it reflects a changing value, it is a Quantity. If it represents an object with properties, it is an Entity.
See also ‘What’s the difference between an entity and a quantity?’.

How can I create a JPEG file from my file?
Print your model diagram to an EPS file using the ‘print’ icon (top right). You can open the EPS file using Acrobat (Pro), from which you can then save it as a PDF. Note that PDF or EPS files should be preferred above JPEG, PNG files as they are vector is based.

How can I make sure that, without giving a value for the radiation of the sun, I can let the simulation run in a loop?
Within LS2 feedback can not be described.