DIFFERENCES BETWEEN EXPERT AND NOVICE DESIGNERS

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DIFFERENCES BETWEEN EXPERT AND NOVICE DESIGNERS

• DESC9099 How Designers Think

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Expert versus Novice

• Case study of an expert and a novice architect
• Expert appears to be 2.8 times as productive as
  novice
• What might be the causes?
• Is it due to some form of strategic knowledge?

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Protocol Studies of Expert and Novice Designer

• Same design task
• Retrospective protocol
• Suwa-Gero-Purcell coding scheme
• Content-oriented analysis

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Sketches by Expert
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Sketches by Novice
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Spectral Distribution of Events
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Time spent drawing for a novice circuit designer
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Suwa-Gero-Purcell Coding Scheme

• D-action draw
• M-action moving without drawing
• L-action look at existing depictions
• P-action perceive visual/spatial features of
  existing depictions
• F-action attach meanings, concepts or functional
  issues to existing depictions
• G-action set-up of goals

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Correlations between Actions
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Primary Action Codes
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Secondary Actions
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Primary Concurrent Actions Correlated with
Depicting Drawings
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Secondary Concurrent Actions Correlated with
Depicting Drawings
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Structures of Concurrent Actions Correlated with
Depicting Drawings
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Structures of Concurrent Actions Correlated with
Depicting Drawings
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Meaningful Versus Non-meaningful
The number of meaningful actions exceeds that of
non-meaningful except for the novices M- and P-
actions
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Novice Versus Expert
The expert is better at perceiving visuo-spatial
relationships
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Conclusions

• Differences between expert and novice
• Productivity
• Rate of cognitive activity
• Structure of concurrent actions
• Strategic knowledge

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Strategic Knowledge

• Expert chunks knowledge into 7 /- 2 concurrent
  actions (Millers magic number for human short
  term memory capacity)
• Novice chunks knowledge into up to 15 concurrent
  actions this fails Millers magic number test
• Strategic knowledge may be thought of as
  successful chunks that have been developed
  through interactions with the task