Usable Software Design sclc.pdf

Apply Usability into how we design source code to be used by our fellow developers.

London software craftsmanship conference

Transcript

1. Usable Software Design There’s no solution without a problem Johan Martinsson, developer. @JOHAN_ALPS
2. @JOHAN_ALPS Design … ... It’s not just what it looks like and feels like. Design is how it works. https://www.flickr.com/photos/8010717@N02/6216457030 CC BY 2.0
3. Alexandru Bolboaca @JOHAN_ALPS leanpub.com/usablesoftwaredesign
4. We’re all designers @JOHAN_ALPS @MARGAUXLERGO 4 The user of software design is the developer Alexandru Bolboaca
5. It’s not the users fault, it’s the designs fault @JOHAN_ALPS Source : http://www.lsd-mag.com/blog/design-inconfortable/
6. A definition @JOHAN_ALPS Nielson (1994)
7. Identify design problems @JOHAN_ALPS
8. Interviews What was difficult to do in the past weeks? What areas of the code were most difficult to understand When were you afraid that your changes might be wrong? Alexandru Bolboaca @JOHAN_ALPS
9. Usability tests « Needs to be cheap enough that you’ll do it! » Watch someone start a story using your code - Don’t help - Ask them to vocalize @JOHAN_ALPS
10. Code review @JOHAN_ALPS I don’t like the code! Is there a usability problem?
11. Team Agreement 1. Code written to be read 2. Easy to find where to modify 3. Minimal ripple effect 4. Simple AND easy to validate 5. Limited duplication A federating concept
12. Parallels with code @JOHAN_ALPS
13. Incitation @JOHAN_ALPS Push or pull? Push, but where? Push!
14. Incitation @JOHAN_ALPS
15. Consistency @JOHAN_ALPS Source : http://lesmoyensgrands.over-blog.com
16. Consistency @JOHAN_ALPS
17. Local Consistency @JOHAN_ALPS - 1972
18. Local Consistency @JOHAN_ALPS
19. Compatibility @JOHAN_ALPS msPaint Adobe Photoshop
20. Compatibility @JOHAN_ALPS
21. Compatibility @JOHAN_ALPS Listen to your users, don’t obey them
22. TDD and usability TDD ◦ Affirmative @JOHAN_ALPS Trial & error ◦ Exploratory
23. TDD and usability @JOHAN_ALPS Resources.delete() Broadcast() resetCurrent() toggleSelectionMode() Delete() Manager.fire() Navigator.delete() Shot gun surgery. Learn/memorability problem
24. TDD and usability TDD requires cognitive mastery. If we don’t have that, then we have a usability problem @JOHAN_ALPS
25. Readability @JOHAN_ALPS Wikipédia Wikiwand
26. Readability @JOHAN_ALPS
27. Information density @JOHAN_ALPS Cdiscount Google
28. Information density @JOHAN_ALPS One level of abstraction Reveal intent
29. Documentation @JOHAN_ALPS When the design is obvious, documentation is waste
30. @JOHAN_ALPS
31. @JOHAN_ALPS
32. Errors @JOHAN_ALPS
33. Make errors impossible @JOHAN_ALPS Google Agenda
34. Make errors impossible @JOHAN_ALPS // Mandatory parameters in constructor // Type parameters
35. It’s not the users fault, it’s the designs fault @JOHAN_ALPS Source : http://www.lsd-mag.com/blog/design-inconfortable/
36. Make errors impossible Two time instantiation Temporal coupling Coupling without cohesion … @JOHAN_ALPS
37. Fix errors @JOHAN_ALPS
38. Encapsulate primitives Fix errors @JOHAN_ALPS
39. @JOHAN_ALPS github.com/martinsson/BugsZero-Kata
40. Rapid feedback @JOHAN_ALPS Amazon Cdiscount
41. Rapid feedback @JOHAN_ALPS $ npm test Executed 364 of 364 SUCCESS (2.663 secs) TOTAL: 364 SUCCESS
42. Funnel of feedback @JOHAN_ALPS IDE Unit tests CI - tests Code review Dev ..etc
43. Dig deeper @JOHAN_ALPS
45. Conclusion It’s not the users fault à Design You’re not your user à Test Starts with Whyà Federating concept @JOHAN_ALPS BUSINESS NEEDS USABLE CODE