Gabriel Spitz Representation 2 Lecture 14 1 Gabriel

Gabriel Spitz Representation (2) Lecture # 14 1

Gabriel Spitz Effective Representation Are choices of labels, icons, controls, instruction, etc. at the interface that capitalize on: What the user already know What is meaningful to the user What the user is comfortable with But effective representation is also making choices that the user is familiar with For example, anthropomorphism 2

Gabriel Spitz Anthropomorphism 3

Gabriel Spitz Anthropomorphism is the creation and attribution of human like characteristics to inanimate objects at the interface 4

Gabriel Spitz A bit too friendly error message 5

Gabriel Spitz Anthropomorphism Is quite popular among children and they seem to like it Adults seem to like animated characters too Cartoons Animated movies such as Shrek, Monsters Inc, The never ending story, etc. 6

Gabriel Spitz Kid. Spiration Example of Kids learning application 7

Gabriel Spitz Anthropomorphism The questions of anthropomorphism at the interface are: Do adults like to only watch animated objects or also interact with them Should application developers promote anthropomorphism 8

Gabriel Spitz Why Anthropomorphism Preece feels that anthropomorphism: Make interaction more fun Motivates and encourages particularly children Helps reduce anxiety At the very least it is harmless bit of fun Shneiderman feels that anthropomorphic interfaces are: deceptive, particularly when they use first person dialog Fun VS. Being Mislead 9

Gabriel Spitz Why Not Anthropomorphism Use of first person at the dialog 10

Gabriel Spitz Why Not Anthropomorphism can also lead people to a false sense of belief that the computer does have human like characteristics Most important however is that most people find it annoying and frustrating 11

Gabriel Spitz Why Not Anthropomorphism Bob Microsoft 1995 Users simply did not like this interface 12

Gabriel Spitz Error messages 13

Gabriel Spitz 14

Gabriel Spitz Error Messages Are the Ouch cry of an application Are an important element of the user interface Often we target error messages to the novice user, but we are all novice at some aspects of the interface 15

Gabriel Spitz When Representation is misunderstood Users make errors, particularly the novice System displays error message User will try to comprehend the “instruction” and refine his/her behavior Hence The choices a designer makes in composing an error message are critical for effective interaction 16

Gabriel Spitz We Are All Novice “I’ve never figured out how to invoke Word’s “format painter” without selecting it from the menu”. (Richard Tenney, Prof CS) 17

Gabriel Spitz Context of Error messages are often displayed when the user: Lacks knowledge Miss understood Slipped The users under these conditions are often: Confused Feels inadequate Feels anxious 18

Gabriel Spitz Role of Error Messages Alert users to the fact that they committed an error Provide users with feedback (this is what you did wrong) – training Support user in recovering from the error (this is what you should do next) – Performance Sooth the user – satisfaction Therefore, error messages are critical aspect of usability 19

Gabriel Spitz Content of Error Messages To be effective under the given circumstances the phrasing of error messages has to be carefully thought out Effective error messages are: Helpful Specific Positive User centered 20

Gabriel Spitz Helpful Error Messages An objective of the error messages is to help users recover from the error and move on with their task To do that the message should: Suggest a course of action Avoid being hostile – do not use terms such as Fatal, Illegal, terminal, etc. , 21

Gabriel Spitz Helpful Error Messages Poor Better Undefined Label (Fortran compiler) Define statement label before use Illegal STA. WRN (Fortran compiler) Return statement cannot be used in a function From: Shneiderman 1998 22

Gabriel Spitz Unconstructive Error Message To be effective a constructive error message should be supported by a constructive dialog box a) There is no disconnect button b) OK, I made a mistake, how do I change my mind? 23

Gabriel Spitz Unconstructive Error Message Don’t use violent language 24

Gabriel Spitz Unconstructive Error Message 25

Gabriel Spitz Specific Error Message Provide the right amount of specificity to resolve the error without confusing the user Long detailed messages are often complex and difficult to follow General messages are not helpful, they simply restate the situation 26

Gabriel Spitz Specific Error Messages Poor Better Syntax error Unmatched left parenthesis Invalid data Days range from 1 to 31 Bad file name File name must begin with a letter From: Shneiderman 1998 27