1. Interaction Techniques Level 2 Prepared by: RHR First Prepared on: Nov 23, 2006 Last Modified on: Quality checked by: MOH Copyright 2004 Asia Pacific Institute of Information Technology HCI & Usability CE 00306-2

2. Human Computer Interaction & Usability Interaction Technique Topic & Structure of the lesson Normans Gulfs of Execution and Evaluation Interaction style –Command Line –Menus –Questions and answers –Form – fills –WIMP

3. Human Computer Interaction & Usability Interaction Technique Learning Outcomes At the end of this lecture, you should be able to: –Select the appropriate interaction technique for the interface design

4. Human Computer Interaction & Usability Interaction Technique Key Terms you must be able to use If you have mastered this topic, you should be able to use the following terms correctly in your assignments and exams: Normans gulf of execution and evaluation Interaction style Command line Menus Question and answer Form – fills WIMP

5. Human Computer Interaction & Usability Interaction Technique Models of interaction Normans Gulfs of Execution and Evaluation –The user formulates a plan of action, which is then executed at the computer interface. When the plan, or part of the plan, has been executed, the user observes the computer interface to evaluate the result of the executed plan, and to determine further actions

6. Human Computer Interaction & Usability Interaction Technique To get something done… –Start with a goal – the goal that is to be achieved –Take action to manipulate something –Check against your goal Models of interaction

7. Human Computer Interaction & Usability Interaction Technique Models of interaction - Execution 2. Intention to act 3. Sequence of actions 4. Execution of the action sequence The world 1. Goals

8. Human Computer Interaction & Usability Interaction Technique The seven stages of action 1.Forming the goal –Something to be achieved –E.g. make a nice meal 2.Forming the intention –Specific statements of what has to be done to achieve the goal –E.g. make a chicken casserole using a can of prepared sauce Models of interaction - Execution

9. Human Computer Interaction & Usability Interaction Technique The seven stages of action 3.Specifying an action sequence – The precise sequence of operators that must be performed to effect the intention – E.g. defrost frozen chicken, open can 4.Executing an action – Actually doing something – E.g. opening the can Models of interaction - Execution

10. Human Computer Interaction & Usability Interaction Technique The world 5. Perceiving the state of the world 6. Interpreting the perception 7. Evaluation of interpretation 1. Goals Models of interaction - Evaluation

11. Human Computer Interaction & Usability Interaction Technique The seven stages of action 5.Perceiving the state of the world –Perceiving what actually happened –E.g. the experience of smell, taste and look of the prepared meal 6.Interpreting the state of the world –Trying to make sense of the perceptions available –E.g. putting those perceptions together to present the sensory experience of a chicken casserole Models of interaction - Evaluation

12. Human Computer Interaction & Usability Interaction Technique The seven stages of action 7.Evaluating the outcome –Comparing what happened with what was wanted –E.g. did the chicken casserole match up to the requirement of a nice meal? Models of interaction - Evaluation

13. Human Computer Interaction & Usability Interaction Technique What are the 7 stages of Normans gulf of evaluation and execution? Quick Review Question

14. Human Computer Interaction & Usability Interaction Technique Interaction Style Dialog between the computer and user. Identification of interaction styles: –Command Line Interface –Menu –Natural Language –Question/ answer and query dialogue –form -fills and spreadsheets –WIMP

15. Human Computer Interaction & Usability Interaction Technique Interaction Style – Command Line First interactive dialog style to be used A mean of expressing instruction to the computer directly using function keys, single characters, abbreviations or whole word command user responds to a prompt on the screen by entering an appropriate command

16. Human Computer Interaction & Usability Interaction Technique Interaction Style – Command Line Benefits of command line: –It offers direct access to system functionality –Quick to use. The command can be applied to many objects at once –Easily extensible –Suitable for experience user

17. Human Computer Interaction & Usability Interaction Technique Interaction Style – Command Line Disadvantages of command line: –Difficult to use –Difficult to learn –Difficult for error correction –Difficult for novice user –Text only data representation Hint: using consistent and meaningful commands and abbreviations

18. Human Computer Interaction & Usability Interaction Technique Review question Can you suggest some guidelines of using the command line interface based on the above advantages and disadvantages?

19. Human Computer Interaction & Usability Interaction Technique Interaction Style – Command Line Design guidelines: Offer maximum flexibility –Conduct task analysis to determine the necessary commands Facilitate command remembering –Use meaningful, descriptive names –Use consistent format of the command line –Provide on-line help

20. Human Computer Interaction & Usability Interaction Technique Interaction Style – Command Line Design guidelines: Facilitate error correction Give feedback on both successful and unsuccessful commands

21. Human Computer Interaction & Usability Interaction Technique Interaction Style – Menus A set of options displayed on screen Relies on recognition rather than recall

22. Human Computer Interaction & Usability Interaction Technique Interaction Style – Menus Benefits of Menus: –Easy to use, reduces memorisation –Structure the users decisions –Easy to program

23. Human Computer Interaction & Usability Interaction Technique Interaction Style – Menus Disadvantages of Menus: –Limited choices per menu –Slow to use in large systems –Multi-user systems slow response times –Can take up a lot of space

24. Human Computer Interaction & Usability Interaction Technique Interaction Style – Menus Can you suggest some guidelines of using the menu and navigation interface, based on the above advantages and disadvantages?

25. Human Computer Interaction & Usability Interaction Technique Interaction Style – Menus Design guidelines: –Group logically related options –Various categories of grouping: Alphabetical Categorical Conventional Frequency –Limit options to 7 per menu approximately, or break into sections –Avoid excessively deep hierarchies –Options that are not available at a given time should be faded (grayed).

26. Human Computer Interaction & Usability Interaction Technique Interaction Style – Question and answer Consists of computer prompt, i.e. question, set of choices, and a response from the user. Next question may depend on previous answer given.

27. Human Computer Interaction & Usability Interaction Technique Interaction Style – Question and answer Benefits of Q&A: –Easy to use for naïve and novice users –Conversational systems –Computer initiated and controlled dialogue

28. Human Computer Interaction & Usability Interaction Technique Interaction Style – Question and answer Disadvantages of Q&A: –Slow to use –Time to read –there is limited support for going back to correct errors that might have been made in earlier questions. –Generally they are quite slow to use - every question must be answered in order to get through the sequence

29. Human Computer Interaction & Usability Interaction Technique Interaction Style – Question and answer Can you suggest some improvements of the question and answer interface, based on the above advantages and disadvantages?

30. Human Computer Interaction & Usability Interaction Technique Interaction Style – Question and answer Design guidelines: –Only one question at a time –Re-display previous answer (s) if replies are linked –Keep sequences compatible with source document or user task model –Display format of acceptable responses

31. Human Computer Interaction & Usability Interaction Technique Interaction Style: Form – Fills Designed for clerical workers –Requires little experience with computers –To enable them to carry out repetitive clerical data collection tasks. –Mimicked paper forms in order to retain the characteristics of the manual task –Designed for a specific type or task.

32. Human Computer Interaction & Usability Interaction Technique Interaction Style: Form – Fills Advantages –Forms offer a neat, structured way of gathering information. Disadvantages –A form has to be designed specifically for each task. –Users will require a certain level of typing skill

33. Human Computer Interaction & Usability Interaction Technique Interaction Style: Form – Fills Can you suggest some improvements of the form - fills interface, based on the above advantages and disadvantages?

34. Human Computer Interaction & Usability Interaction Technique Interaction Style: Form – Fills Design guidelines: –Text box : Maximum size of text-box can be determined beforehand. –In many fields it is possible to provide a default value for a data field –In some forms, certain values might be required, other optional. For required items, program might not proceed to other fields until value is entered.

35. Human Computer Interaction & Usability Interaction Technique Interaction Style: Form – Fills Design guidelines: –Interdependencies can be incorporated in the program. For example, if one element asks if user is pregnant, then 'female' is automatically entered in the 'sex' field.

36. Human Computer Interaction & Usability Interaction Technique Interaction Style: WIMP Windows, icons, menus and pointers The user carries out some physical action (e.g. clicking, dragging) rather than typing commands with complex syntax The results of the action are seen immediately and, usually, actions are reversible

37. Human Computer Interaction & Usability Interaction Technique Interaction Style: WIMP Advantages –Novices can learn the basic functions quickly, usually through demonstration and practice rather than from formal instruction or a manual. –Intermittent users can retain the main operational concepts of the interface because it involves visual recognition. –Error messages are rarely needed because most actions are reversible.

38. Human Computer Interaction & Usability Interaction Technique Interaction Style: WIMP Advantages –There is immediate feedback as to whether or not the user's goals have been achieved. –Users are less anxious, again because they know actions can be reversed.

39. Human Computer Interaction & Usability Interaction Technique Summary of Main Teaching Points Interaction is the heart of all modern interfaces and is important at many levels from the ordering of screens to the clicking of a button.

40. Human Computer Interaction & Usability Interaction Technique Q & A Question and Answer Session