KidSim

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KidSim

• Programming for Children Part II

CSCI 6304 Visual Languages
Yingxin He
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Agenda

• Introduction
• Components of KidSim
• Design of KidSim
• Cocoa Demo
• Empirical Evaluation
• Cognitive Dimensions
• Discussion

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Introduction

• The end-user programming problem
• -- Enable end users to program
• KidSim and Cocoa
• -- 1994, KidSim.
• -- 1996, Cocoa.
• -- 1998, Died.
• -- stagecast.

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Introduction (Cont.)

• The Goal of KidSim
• -- To program without learning conventional
  programming
• languages.
• The key idea
• -- Direct manipulation
• Programming by moving manipulating, drag
  and drop etc.
• -- programming by demonstration
• System records the user performance and
  generalizes these
• actions to create a rule that will be
  automatically performed

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Components of a KidSim Simulation

• Board
• Control Panel
• Appearance Editor
• Rule Editor
• Variables
• CheckList
• Other elements

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Components of a KidSim Simulation (Cont.)
Board
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Components of a KidSim Simulation (Cont.)
Controls
Create Tool click on the board to create a new
type of piece
Paint Tool click on a piece to edit its
appearance
Rule Record Tool - click on a piece to record a
rule
Clock Controls - "Stop" or "Run" the world
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Components of a KidSim Simulation (Cont.)
Controls
Rewind - run the world backward, undo up to 1000
actions
Step Controls - run the world backward or forward
one step at a time
Clock Speed - adjust the world's running speed
from fast to slow
Delete Tool - click on anything to delete it.
Hold the shift key to delete more than one thing.
You can also delete things by selecting them then
hitting the delete key.
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Components of KidSim Simulation (cont.)
Appearance Editor
From Cocoa reference manual
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Components of KidSim Simulation
(cont.)
Rule Editor
If there is an empty space in the right, Then
move into it.
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Components of KidSim Simulation (cont.)
Variables
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Components of KidSim Simulation (cont.)
CheckList
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Design of KidSim

• KidSim adopted OO design, but it is not
  complete OO.
• Types
• -- abstraction of a particular kind of
  characters,
• -- correspond to classes in OOP.
• Characters
• -- A character is an instance of a particular
  type,
• -- corresponds to objects in OOP.

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Design of KidSim(cont.)

• Appearances and properties
• -- Appearances display what the character
  looks like.
• -- Properties maintain information about the
  character.
• -- They correspond to instance variables in
  OOP.
• Rules
• -- define what a character is to do,
• -- if, then statements,
• -- correspond to methods in OOP.

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Design of KidSim(cont.)

• Rule Execution
• -- On each clock tick, every character is
  given a chance to act,
• -- Each character searches its rules and
  performs the first rule
• that matches its current state.
• -- problems with parallel execution
• If I am next to an empty chair, sit in
  it.
• -- Sequential execution
• At each clock tick, the first character
  that was place on the
• board searches its rule list, and
  executes the first rule that
• matches its current state.
• This process continues until the last
  character gets its chance.
• -- Problems with sequential execution
• Hidden dependency! Premature commitment!
  Error-proneness!

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Design of KidSim(cont.)

• Inheritance
• -- Each type has its own properties,
• appearances, and rules,
• -- Changes to one character affect all the
• instances of the same type,
• -- Each character can have its own value
• of a property and its own drawing for
• each appearance,
• -- Single level inheritance,
• Viscosity! Abstraction!

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Demo
See http//www.cs.dal.ca/yhe/oceanlife.html for
the internet version demo
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Empirical Evaluation

• Reliability
• -- It consumed large amounts of disk space
  and
• RAM, the minimal RAM requirements is
• 1.5MB.
• -- The system is slow and crashes
  frequently.
• Engaging thinking
• -- Children of age 12-14 can master the
• programming environment,
• -- enjoy using the system,
• -- fire their imagination.

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Empirical Evaluation (Cont.)

• Rule comprehension
• -- the children seem to spend very little
  time reading back over the
• rules they have already written for an
  agent.
• -- One pair of children have been producing
  multiple copies of very similar
• rules. Of the 15 rules written, only 6
  can really be regarded as distinct
• rules.
• Programming concepts
• -- No programming concepts have been
  learned.
• -- The interfaces are too easy and, thereby
  do not encourage
• reflection and learning.
• http//www.psychomogy.nottingham.ac.uk/staff/dg/Ki
  dSim/Interact/Kidsimdg.html

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Cognitive Dimensions

• Closeness of Mapping
• Visibility
• -- Only one board for programming,
• -- But the space is limited.
• Abstract Gradient and Viscosity
• -- Single level inheritance

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Cognitive Dimensions (cont.)

• Hidden Dependency, Premature Commitment, and
  Error-proneness
• -- Rules are executed sequentially in each
  clock tick,
• -- Different orders in which the same set of
  characters are created
• can course different computing results.

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Discussion