Perception TopDown and BottomUp Processing n TopDown Goaldriven
![Perception: Top-Down and Bottom-Up Processing n Top‑Down Goal‑driven n Processing dominated by context, expectations, Perception: Top-Down and Bottom-Up Processing n Top‑Down Goal‑driven n Processing dominated by context, expectations,](https://slidetodoc.com/presentation_image/423649b625b7deef5b3ae0d0562d3252/image-1.jpg)
Perception: Top-Down and Bottom-Up Processing n Top‑Down Goal‑driven n Processing dominated by context, expectations, hypotheses, "the big picture" n n Bottom‑Up Data‑driven n Processing dominated by characteristics of stimulus, "details” n Feature analysis n n ISE 412 Both types of processing occur simultaneously and are highly interactive. 1
![Some examples n Problem-solving ¨ Wheel of Fortune ¨ Crossword puzzles ¨ Design n Some examples n Problem-solving ¨ Wheel of Fortune ¨ Crossword puzzles ¨ Design n](http://slidetodoc.com/presentation_image/423649b625b7deef5b3ae0d0562d3252/image-2.jpg)
Some examples n Problem-solving ¨ Wheel of Fortune ¨ Crossword puzzles ¨ Design n ISE 412 Hearing: conversation, listening to music, etc. 2
![An example … n Listen to the song and write down the words as An example … n Listen to the song and write down the words as](http://slidetodoc.com/presentation_image/423649b625b7deef5b3ae0d0562d3252/image-3.jpg)
An example … n Listen to the song and write down the words as you hear them. n To discuss … ¨ What were doing during “bottom-up” processing (with and without visual cues? ¨ What ISE 412 were you doing during “top-down” processing? 3
![Perception of print n Feature analysis: n n n Bottom-up, we perceive features of Perception of print n Feature analysis: n n n Bottom-up, we perceive features of](http://slidetodoc.com/presentation_image/423649b625b7deef5b3ae0d0562d3252/image-4.jpg)
Perception of print n Feature analysis: n n n Bottom-up, we perceive features of letters, words Involves pattern matching Top-down, we use context of surrounding letters and words to limit alternative interpretations Examples: Sawple ISE 412 Sample 4
![Context-Data Tradeoff n Assuming limited display size for text, trade off context and data Context-Data Tradeoff n Assuming limited display size for text, trade off context and data](http://slidetodoc.com/presentation_image/423649b625b7deef5b3ae0d0562d3252/image-5.jpg)
Context-Data Tradeoff n Assuming limited display size for text, trade off context and data quality: n Many words: High contextual redundancy (easy to comprehend) ¨ Poor data quality (hard to read) ¨ n Few words: Good data quality (easy to read) ¨ Low contextual redundancy (hard to comprehend) ¨ ¨ Example: weather alerts on a heads-up display WEATHER ISE 412 Will encounter bad weather 5
![Creating context: Redundancy gain n n ISE 412 The information is presented in more Creating context: Redundancy gain n n ISE 412 The information is presented in more](http://slidetodoc.com/presentation_image/423649b625b7deef5b3ae0d0562d3252/image-6.jpg)
Creating context: Redundancy gain n n ISE 412 The information is presented in more than one way. If the viewer is not able to process the information in one mode (e. g. , color blind) can rely on another. Reaction time is faster if information is presented redundantly. Promotes top-down processing. 6
![Object perception n Objects are perceived holistically i h c hi er g on Object perception n Objects are perceived holistically i h c hi er g on](http://slidetodoc.com/presentation_image/423649b625b7deef5b3ae0d0562d3252/image-7.jpg)
Object perception n Objects are perceived holistically i h c hi er g on l s ? W n Empirical evidence on card‑sorting tasks: n objects categorized more quickly and accurately than "separate" displays such as numbers or words ♣ ♣ 4 of Clubs Carrot ♣ ♣ ISE 412 7
![Advantages & disadvantages … n Advantages n Disadvantages ISE 412 8 Advantages & disadvantages … n Advantages n Disadvantages ISE 412 8](http://slidetodoc.com/presentation_image/423649b625b7deef5b3ae0d0562d3252/image-8.jpg)
Advantages & disadvantages … n Advantages n Disadvantages ISE 412 8
![Object perception n Wickens et al. studies: ¨ object displays facilitate performance on information Object perception n Wickens et al. studies: ¨ object displays facilitate performance on information](http://slidetodoc.com/presentation_image/423649b625b7deef5b3ae0d0562d3252/image-9.jpg)
Object perception n Wickens et al. studies: ¨ object displays facilitate performance on information integration tasks GPM, y 5. 5 5. 9 6. 5 3. 3 3. 6 4. 6 2. 9 3. 6 3. 1 4. 9 ¨ separable ISE 412 Wt. , tons 3. 4 3. 8 4. 1 2. 2 2. 6 2. 9 2 2. 7 1. 9 3. 4 displays support diagnosis tasks 9
![Examples … Phone ISE 412 Easy Difficult A 0 2 B 1 2 C Examples … Phone ISE 412 Easy Difficult A 0 2 B 1 2 C](http://slidetodoc.com/presentation_image/423649b625b7deef5b3ae0d0562d3252/image-10.jpg)
Examples … Phone ISE 412 Easy Difficult A 0 2 B 1 2 C 0 3 10
![Implications for display design n Optimize bottom-up processing ¨ size, contrast, font (for text), Implications for display design n Optimize bottom-up processing ¨ size, contrast, font (for text),](http://slidetodoc.com/presentation_image/423649b625b7deef5b3ae0d0562d3252/image-11.jpg)
Implications for display design n Optimize bottom-up processing ¨ size, contrast, font (for text), appropriate upper/lower case ¨ raw data on object displays n Optimize top-down processing ¨ avoid abbreviations & acronyms whenever possible ¨ provide context (more words in text, recognizable object displays) ¨ restrict “vocabulary” (text and picture) and optimize distinction between words/pictures n n ISE 412 Evaluate tradeoffs Usability testing in context 11
![Some fun examples: http: //exp. kyb. tuebingen. mpg. de/web-experiment/list. html http: //www. grand-illusions. com/index. Some fun examples: http: //exp. kyb. tuebingen. mpg. de/web-experiment/list. html http: //www. grand-illusions. com/index.](http://slidetodoc.com/presentation_image/423649b625b7deef5b3ae0d0562d3252/image-12.jpg)
Some fun examples: http: //exp. kyb. tuebingen. mpg. de/web-experiment/list. html http: //www. grand-illusions. com/index. htm ISE 412 12
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