HCPro Lecture 10 ( ):

Transcription

1 HCPro Lecture 10 ( ): Usability goals, idea generation techniques Jarmo Palviainen

2 Main Themes of the Lecture Setting usability/ux goals Ideation techniques

3 Usability goals & requirements At the early stage: goals/requirements Requirements (see lecture 6): What the system does, not how Usability goals: also how in a certain way (performance, experience, learning etc.) Goals can be formed by finding out the current level Not possible for a new concept Later compare results to goals When can we stop iterating? Did the project succeed Maybe later you will understand better, what is an adequate level HCD standard says that you should describe at least measures for efficiency, effectiveness and satisfaction.

4 Examples of usability goals 1/3 "Data entry clerks will be able to input data from the forms with 98% accuracy in a mean time of less than 10 minutes. The mean SUMI score will be greater than 50. [ISO 13407] (efficiency) All users consider the new system better than the old one (satisfaction) Less than 5% of the users need to use the instructions in the first time of use. (effectiveness)

5 Examples of usability goals 2/3 Usability goals are written in a format that contains following data: To which user group is this applied Pre-conditions for measuring usability What criteria (attributes) are used What and how they are measured In brief e.g. System xxx usability specification For 90% of the users, their work has become remarkably more efficient after taking the new system into use User population: All users Pre-conditions: Will be measured after one week active use Attribute: Efficiency

6 Examples of usability goals, 3/3 Example of a longer version: System usability spesification User population: All users Pre-conditions: Measurements after one week use Attribute Measure Worst case Efficiency Efficiency Mistakes during task Time used 5 or more 10 min or more Lowest acceptable level Planned level Best level Current level 5 min 3 min 1 min 10 min In addition: tell for each attribute the source, from which the data is collected

7 Defining the current level of usability/ux Setting the goals should be based on the status of the current or equivalent systems Recognize the problems in the current products Avoid problems found in other products Benchmark for usability/ux Select the most important tasks and user groups to be tested/participate the tests Typically tested by few users, think aloud Categorizations for findings based on importance/frequency Expert evaluations can be used too Consider using standardized questionnaires to determine the level of UX/usability (e.g. Attrakdiff, SUMI ( Net Promoter Score)

8 Setting the usability goals Found measures can be used when defining usability goals 1) Define measurable goals Concrete Criteria, that is testable Soon after the introduction of the system or later, in active use To emphasize meaning of usability in the early stage To express what the new system should be like, so that the designers and implementers can act accordingly

9 Setting the usability goals 2) Choose the user groups and tasks for the goals (these hopefully were found when studying the current level) 3) Decide the criteria (considering the current status), e.g.: Acceptable task finishing time Optimum end result (effectiveness) How efficiency is evaluated (consider what mistakes the user can make) Satisfaction goals Load for the support organizations Decide what attributes are the most important Understandability, learnability, operability and attractiveness Evaluate, when testing the prototype

10 What you want to measure micro vs. macro [Hornbæk 2006]

11 Measures for diffent areas in usability [Hornbæk 2006]

12 Usability goals: the attributes & metrics Effectiveness (how well suited to the task) Success % of the task Frequency of using different features Problems the users had The quality of the outcome

13 Usability goals: the attributes & metrics Efficiency Task completion time Features or operations needed to complete the task, use e.g. GOMS Time used for seeking for information (learnability). Time used for using on-line help Time spent on handling errors Satisfaction User attitudes towards the system, e.g. chosen likert scales of seven, SUMI (Software Usability Measurement Inventory), Net Promoter Score

14 Usability goals: the attributes & metrics Learnability How quickly a novice user can accomplish certain tasks (often the learning curve gets more gradual) The time needed to use the system or to reach a certain level of performance Problems occurred during getting the necessary skills Time spent on searching for information (from documents/on-line help) Frequency of using On-line helps Time spent on recovering from mistakes Frequency of certain or all error dialogs Time needed to maintain learned information about the system Time to re-learn after a pause Frequency of help needed to solve a problem

15 Usability attributes, Usability properties and Usability patterns Make the goals to support the design and the design to support the goals! This will be explained later Lecture: Usability & software architecture Usability framework [Folmer & Bosch 2003, Juristo & al 2003]

16 16 Producing ideas and design solutions

17 General about creating ideas Expertise and collecting information before hand Creativity is also based on knowledge, not only ideas and associating Technology, human needs, market, own resources A good design method ensures that sufficient knowledge is gained before creating the design solution OR is it so? What is sufficient?

18 Producing ideas Make sure you know what it the problem to be solved Multi disciplinary group work, E.g. Rapid7 [Kylmäkoski 2006] In individual level, creativity is positive criticism, ability to listen to the others ideas and use them when developing it further [Välimaa et al. 1994] First amount, then quality!

19 Ideation techniques (Jokinen) Idea walk (Ideakävely) Brainstorming techniques (Aivoriihitekniikat) the traditional (Alex Osborne 1939) Expressiveness, Postpone idea evaluation, Quantity versus Quality, Piggyback Ideas [wikipedia] Method 635 / Brainwriting) The Gordon technique Grounded brainstorming [Beyer & Holtzblatt] Altering method (Osborn s question list) (Muuntelumenetelmä) Double team Tuumatalkoot Synectics Love-Hate

20 What to do with the ideas Once you have large number of ideas, you need to evaluate the quality Collective evaluation helps solving problem of ideas becoming personal Often even using ideation techniques helps here Try to get positive features of all ideas integrated into one or few ideas

21 Questions helping at evaluating ideas Does the idea work? Can it be implemented? Does it improve the current convention? Does it lower the expenses? Does it increase productivity? Does it improve quality? Does it improve safety? Does it improve working conditions? Does it affect moral? Would people really like it? Is it temporal or long lasting solution? Is it simple and understandable? Do others approve it? [Heikkilä ja Heikkilä]

22 References Beyer, H. Holtzblatt, K. Contextual Design: Defining Customer-Centered Systems. Morgan Kaufmann, 1998 Heikkilä, J., Heikkilä, K. Innovatiivisuutta etsimässä. Irtiottoa keskinkertaisuudesta. Helsinki: Kauppakaari, Nielsen, Usability Engineering, Morgan Kaufmann, 1994 Koski, J.T., Banappelsiini, Gummerus Kustannus Oy, Koski, J.T., Tuominen, S., Kuinka ideat syntyvät - Luovan ajattelun käsikirja. WSOY, 2004.