CHI 01 Tutorial Proposal

Cognitive Factors in Design: 
Basic Phenomena in Human Memory and Problem Solving.
Tom Hewett
Department of Psychology, Sociology, and Anthropology
Drexel University, 
Philadelphia, PA  19104,  USA
Phone:  +01-215-895-2461
FAX:      +01-215-895-1333
email:   hewett@drexel.edu
   
Description of material covered in the course (combined with description and samples of materials included in the tutorial notes):

Anticipated Table of Contents
Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 	i
Biographical Sketch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	ii
Agenda	 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	iii
Course Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	iv
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 	1
Preliminary Observations and Caveats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	4
Human Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 	7
The Demonstrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	11
	Some characteristics of long-term memory . . . . . . . . . . . . . . . . . . . . . . . . .	11
	Some characteristics of short-term or working memory . . . . . . . . . . . . . 	18
	Thinking about HCI: Questioning a design claim . . . . . . . . . . . . . . . . . . . 	20
	One relationship between long-term and working memory . . . . . . . . . 	23
	Elaborative rehearsal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 	25
	Thinking about HCI: A design example . . . . . . . . . . . . . . . . . . . . . . . . . . . .	29
	Importance of understanding in LTM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 	33
	LTM is integrative, extrapolative and even creative . . . . . . . . . . . . . . . . . 	37
	Thinking about HCI: User knowledge structures are important . . . . . .	44
	Memory and HCI: A summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 	45
Memory Outline and Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	46
Problem Solving . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	51
	Problem representation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	54
	Problem solving schemas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	55
		Problem solving set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	56
		Some observations about set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	58
		Functional fixedness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	59
	Thinking About HCI: Breaking the set or 
		escaping from functional fixedness . . . . . . . . . . . . . . . . . . . . . . . . . . . .	61
	Another side effect of schemas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 	65	
	Representation and re-representation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	67
	Complex problems may require subgoaling . . . . . . . . . . . . . . . . . . . . . . . . 	71
	Some rules of thumb for effective problem solving . . . . . . . . . . . . . . . . .  	72
	A trap for the unwary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	74
	Problem Solving and HCI: A summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . 	75
Tutorial References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 	76
Suggested Books for Further Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 	80
Appendix A: Example and Problem Solutions . . . . . . . . . . . . . . . . . . . . . . . . . 	85
Appendix B:  Some Basic Perceptual Phenomena . . . . . . . . . . . . . . . . . . . . . .  	88
Appendix C: Tips Desk Accessories User Documentation . . . . . . . . . . . . . . .	100 
Appendix D: Memory Lists and Directions . . . . . . . . . . . . . . . . . . . . . . . . . . . .	104

	The tutorial notes are prepared as a student workbook so that the attendees are able to write down their responses to the demonstrations and to record data in the tables and graphs provided.  In addition, ample white space is provided for comments and notes.   (Feedback from attendees over the years suggests that this format for the notes is quite popular with several of them as they see it as being more of a resource that simple duplication of presentation slides.)  Integrated into the notes are a series of “thought questions” to focus the student’s attention on significant aspects of the demonstration and its potential implications for design of human-computer interactions.  In addition, the notes contain annotations explaining the significance of each demonstration and what is to be learned from it.  (In the case of the memory demonstrations this is provided in a separate section which follows the memory demonstrations so as not to prematurely give away the point of the demonstrations.)  The notes contain a complete references to all demonstrations so that original source materials which may not be included in the notes can be easily found.  In addition,, the notes contain a bibliography of sources for additional reading on Cognitive Psychology, memory, problem solving, and applications to human-computer interaction.

	Since the full set of tutorial notes runs to over 100 pages and is undergoing revision, this proposal provides three samples of the material covered by the tutorial and notes.  First a list and a parenthetical allusion to the demonstrations used.  Next the proposal provides an sample of some of the thought questions used to focus the student’s attention on the relationship between the phenomena and their potential implications for design of human-computer interactions.  Some questions are explored during the tutorial, others are left as an exercise to the student.  Third, the proposal provides that portion of the notes which annotates the memory demonstrations and indicates on which page of the current set of notes the demonstration can be found.  (While these page numbers are subject to change in the upcoming revision, this feature will be maintained.)

Topical Outline for Tutorial Demonstrations

Memory (More than half day spent on this topic)
	Clustering and organization in recall
		(John, grape, dollar, orange, etc.)
	Characteristics of long-term and short-term memory 
		Long-term vs. short-term? 
			(Lists with and without counting backwards)
		Characteristics of short-term memory
			7 + or - 2 "chunks"  (Seven Little Dwarfs)			
			What is a "chunk"  (Subitizing)
			Accessibility of contents of long-term memory
				(FB IPH DTW AIB MTV ARC etc.)
		Transfer from short-term to long-term memory 
			Not maintenance rehearsal  (last t word)
			Mnemonics--elaborative rehearsal 
				(Peg words and grocery shopping list)
		Characteristics of long-term memory 
			Importance of retrieval cues in long-term memory
				(Inappropriate cues)
			Importance of organization in long-term memory
				(Titleless paragraph)
			Long-term memory is integrative, extrapolative, and even creative
				(Integration of sentences in memory)
				(Rumor transmission)

Problem Solving (Less than half day spent on this topic)
	Processes interact  (Nine dots problem)
	Definition of a problem
		Initial state--chess board at start; Goal state--winning position; Gap; 				Operators--pieces; Conditions on operators--rules of game	
	Schemata (50 min.) and reasons for thinking they exist
		Earlier, related concepts
			Set -- Luchins
			Functional fixedness -- Maier
		We start processing before knowing the entire problem
			(Polar bear problem)
	Importance of representation
		(XIV + XXVI) = (14 + 26)
		(mutilated chess board and matchmaker problems)
	Rules of thumb for effective problem solving
		(A problem is something that doesn't solve easily)
		(If at first you don't succeed, try something different)
		(Look to knowledge or to representation)
		(Try any piece of a complex problem you do not understand)
	A trap for the unwary   (O T T F F S S .....)
Tutorial Content References  (to be included in tutorial notes)
Suggestions for Further Reading  (to be included in tutorial notes)

Sample Thought and Discussion Questions for Memory Demonstrations

		Do you notice anything about the words from list # 1 as you have written 		them down?
		What does it imply when you get back more information than 			was put in?
	Who wrote down the word "orange?"
		Why?
	Were any other words recalled that didn't belong on the list?
		What relationship do these errors have to words on the list?
	What do these results imply about the information stored in LTM?
	What accounts for the difference between recall on this list and List 1?
	What words did you write down that didn't belong on the list?
	What is the relationship between these errors and the words on this list?
	Do you notice any difference between the errors on List 1 and those on List 3?
	Does a comparison between the errors on List 1 and those on List 3 suggest anything to you about possible sources of errors in working with a computing system?  
	Does this comparison suggest any thing about possible differences between the errors made by novices and the errors made by experienced users of computing systems?  
	If there are differences in the kinds of errors made by novices and by experienced users, what would be the implications of such differences for error trapping and error messages?
	What accounts for the difference between recall on this list and on the last list?
	Does this suggest anything about the kind of memory aids one might want to design for users who will be working in environments where there is an on-going flow of information and a high level of distraction?
	Given these results, would you expect the user of an interactive 	computing system to be able to recall command strings without benefit of practice, or where practice involves simple repetition of commands?
	Do the strategies used to create mnemonics suggest anything about structuring the user's interaction with tutorial materials during training?
	What are the implications of this effect for new users when they are moved from training to actual usage of the system?  Does this suggest anything about how training should be structured?
	What does this effect suggest about the structure of helpful help systems?
	Consider the implications of this effect for training and for interface design.  For example, consider the importance of titles and the wording of menus, etc.   Will terms that are meaningful for designers and programmers carry that same meaning, or any meaning, to users?
	Does this effect suggest anything about ways to organize or structure the information in user training sessions or in user manuals and other forms of system documentation?

	What do these results suggest about the need to create and regularly update planning documents for use by designers and programmers during development of a complex system?
	What do these results suggest about users interacting with a complex system and trying to make sense out of it? 
	What implications do these effects have for training of users?
	What can happen to your well thought out explanation of a complex system as the information is passed from user to user?
	What are the implications of these effects for the process of conducting user testing and evaluation of interactive computing systems?
	What are the implications of this effect for any environment where users discuss the system and its operation with each other?

Memory Demonstrations Annotations

	Clustering and organization in recall. (Pp. 8-10)
		The first demonstration is adapted from Bousfield (1953).
		The organization of memory provides one basis for postulating  			the existence of semantic networks.
	The second demonstration (p. 11) is taken from an instructor's manual by Lindsay and Norman (1972).  The authors claim the original demonstration was written down on a napkin in an English pub by memory researcher Endel Tulving.  Its importance is discussed below.
	Characteristics of long-term and short-term memory.
		The Serial Position Effect--A difference? (Pp. 12-14)
	This demonstration is adapted from Bott and Munroe (1977).  While there is controversy about whether the difference between these two curves is produced by two separate memories--STM and LTM--or by the use of two different processing strategies (Bernbach, 1975), there seems to be little doubt that there are two different components making up the serial position effect which shows in a comparison between the two lists.
	Some characteristics of short-term memory. 
		Capacity (p. 15)
			7 plus or minus 2 "chunks"  (Miller, 1956)
			Metaphor:  The seven little dwarfs
		What is a "chunk?" (p. 15)
			e.g., Subitizing and Chunking
	The capacity of STM to handle large amounts of information is facilitated by the ability to chunk information.  Apparently, almost anything which can be used in the organization of long-term memory can form a basis for chunking.

		Accessibility of contents of long-term memory (p. 15)
				This second demonstration is taken from Bower & Springston (1970).  The "capacity" of STM may be limited to about seven chunks, but the density of information in one of those chunks may vary a great deal.  It appears, however, that chunking does not occur until some information in LTM is activated.  The pause between each group of letters allows for encoding of the letters as a chunk.  (Probably after a "look up" in LTM.)
	How is information maintained in short-term memory? (p. 16)
			Maintenance rehearsal: e.g.,  a phone number
	How does information transfer from short-term into long-term 		memory?
		It is probably not maintenance rehearsal. (p. 17)
	"Last t word" demonstration is from Craik and Watkins (1973)
	Generally, the results indicate that the interval between the t words, which  presumably is a measure of amount of rehearsal, has little or no effect on recall, suggesting that maintenance rehearsal in ineffective at transfer of information into long-term storage.
		Elaborative rehearsal--e.g., mnemonics (p. 18-19)
	Generally, most mnemonic strategies use such things as 	rhyming and imagery to enhance recall by creating patterns or 	chunks and by relating the information to already well known cues (Bower, 1970).  A good,  popular press book on mnemonics is The Memory Book by Lorayne and Lucas (1974).  Mnemonics and their operation also represent an example which illustrates nicely why Psychologists tend to distrust unsupported intuitions.  The work of Wollen, Weber, & Lowry (1972) suggests that the crucial variable in making up mnemonic images is not the bizarreness of the image per se, but rather the interactivity of the component objects in the image.
	Some characteristics of long-term memory.
		Importance of retrieval cues in LTM.  (List #2, finally!) (p. 20-21)
Important points:
	1.  Notice the generally high accuracy of cued recall (except for the last two lines)
	2.  Notice that although the cues were not supposed to be 	learned most participants do learn them well enough to realize that hints 19 and 20 are not correct.  Some learned them well enough to 	be able to remember the cues as well.
	3.  Notice that when one is given a reasonable hint but one that differs from the one used during learning there is no particular benefit from the cue.
		In other words, the organization imposed upon the material at the time of learning influences its later accessibility.  This also suggests a possibility as to why recognition memory is generally better than recall memory--the availability of cues during recognition.
		Importance of understanding in LTM. (p. 22)
	The titleless paragraph was adapted from Bransford & Johnson (1973), and illustrates the degree to which understanding of information, and being able to relate new information to information already in memory, influences the ability to remember the new information.  Unless new material that is experienced fits within an existing organizational framework in memory, there is apt to be little or no recall of it later.
		LTM is integrative, extrapolative and creative. (Pp. 24-29)
	The Integration of Information in Memory demonstration is adapted from Bransford & Franks (1971).  The recall of sentences on the second list which did not appear in their complete form on the first list clearly supports the idea that coherent memory structures can be built up from a set of component parts.  
	The Rumor Transmission demonstration is adapted from 	Allport & Postman (1947).  Their studies reported on a more 	technical, qualitative analysis which can be done on these kind of data.  Their analysis focused upon processes such as : 1) leveling-- a tendency to shorten and drop out detail; 2) sharpening--the highlighting and elaborating particular elements; and 3) assimilation--distortion in direction of listener's expectations, habits, and, sometimes attitudes and prejudices.  This quantitative analysis is more complex, however, because it requires establishing a set of scoring rules which clearly define what a "detail" is, what counts as a distortion, and what weights should be assigned to different kinds of distortion.
	Bartlett (1932) demonstrated that similar results occur for 	recall within a single individual.  The categorization scheme used by Bartlett includes:
	omission--specific details drop out, information that is 	illogical or does not fit with expectations drops out;
	rationalization--information is added that helps explain 	inconsistencies;
	dominant theme--some themes, and the information related to them, become prominent;
	transformation of information--unfamiliar words are 	transformed into new ones;
	transformation of sequence--time sequences change, and 
	participant's attitude--effects of attitudes show up.
	A final caution. (p. 30)

Justification of this tutorial for a CHI audience:  This tutorial covers content central to the psychology of human-computer interaction in a way that provides attendees with the resources needed to learn more about the psychology of human-computer interaction and which sensitizes them to strengths and limitations of cognitive processes in themselves and others.  It also articulates some of the reasons why cognitive psychology is a supporting discipline for work in human-computer interaction.

How the tutorial will be conducted:  This full day tutorial relies upon demonstrations, “minds-on” exercises and mini-lectures to introduce participants to a number of basic processes and phenomena of  human memory, and human problem solving.  Extended examples and thought questions in the notes provide illustrations of how the knowledge gained in the tutorial might be applied to human-computer interaction design.

Schedule of events and times:
0900  Introductory Remarks
0915  An Overview of Human Memory
0930  Memory Demonstrations and Implications
1030  Coffee Break
1100  Memory Demonstrations and Implications
1230  Lunch
1400  Conclude Memory Demonstrations
1430  Problem Solving Demonstrations and Implications
1530  Coffee Break
1600  Conclude Problem Solving Demonstrations
1730  Adjourn

Providing a more finely grained schedule would be unrealistic since it is often necessary to edit out material on the fly depending upon audience response and the types of questions, etc. which get raised.

Describe and provide samples of materials that will be included in notes:  See description above of material to be covered in the course.

Tutorial history:  The demonstrations and exercises in this tutorial have been classroom tested in both Graduate and Undergraduate courses in both Cognitive Psychology and Human-Computer Interaction.  Earlier versions of the tutorial were offered at CHI+GI 87, HCI '87, HCI '89, and HCI '91.  The current version of this tutorial has been offered at EUROGRAPHICS '92, HCI '92, OZCHI ‘93 and OZCHI ‘95.  It was also conducted at the Loughborough University of Technology for the UK Chapter of the EUROGRAPHICS association (1993, Jun.).  It has also been conducted for members of the Austrian Computer Society (1996, Dec.) and at INTERACT 97.  It is scheduled to be offered at INTERACT 99.  This tutorial was the top rated tutorial offered at CHI ‘95.  It drew approximately 180 participants at CHI ‘96, approximately 80 participants at CHI ‘97, well over 100 at CHI ‘98, and approximately 130 participants at CHI ‘99.  At CHI ‘96, CHI ‘97, CHI ‘98 and CHI ‘99 this tutorial was ranked as one of the top 5 or 6 tutorials offered.  The audience at CHI 2000 also rated the tutorial highly.

Modification of tutorial:  The feedback from the forms completed by the CHI ‘00 attendees brought no surprises.  The tutorial continues to be very popular, most of what is there people want to keep, and a subset of the attendees want a strengthening of the connection between the presentation of the material and ways to apply the material.  I continue to talk with attendees to both gather examples from those for whom the connections are obvious and to try to understand how to bridge the gap for those who do not see the connection.  Thus the tutorial materials undergo a continuous evolutionary process which seems to be working in that there there does seem to be a trend over the years in improving the connections for those who have difficulty.  Although I have not yet incorporated all of the suggestions made by reviewers in prior years (most notably those which recommend an expansion of content), I am looking at some demonstrations which may work for strengthening the problem solving section to highlight analogical problem solving explicitly.  I continue to work on expansion and elaboration upon the various thought questions and examples illustrating application of the material to interaction design to increase in the amount of time devoted to coverage of some of the implications of the material for designing interactive systems.  Some of the other issues raised by attendees in earlier years--e.g., lack of opportunity for class discussion of applications can only be addressed by limiting attendance or by expanding the tutorial to a two day format.  While I have experimented with a two day format and audiences limited to 25, I’m not sure I’m convinced that that would be a good way to go for CHI.