Chapter 2 — Computing systems
Lesson map
Lesson 02 published. Map, example, EX004.
flowchart TD
N0["Learning outcomes"]
N1["2.1 Parts of a system"]
N2["2.2 Points of interaction"]
N3["2.3 A user journey"]
N4["Synthesis"]
N0 --> N1 --> N2 --> N3 --> N4
N4 --> EX["Worked example"]
EX --> Q["Exercise EX004"]
Logical drawing
flowchart LR
N0["Learning outcomes"]
N1["2.1 Parts of a system"]
N2["2.2 Points of interaction"]
N3["2.3 A user journey"]
N4["Synthesis"]
N0 --> N1 --> N2 --> N3 --> N4 --> Q["EX004"]
[Learning outcomes]
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v
[2.1 Parts of a system]
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v
[2.2 Points of interaction]
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v
[2.3 A user journey]
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v
[Synthesis]
|
v
[Worked example] --> [Exercise EX004]
Learning outcomes
You will (1) describe the parts of a computing system staff use daily; (2) identify where people interact with security; (3) map a simple user journey.
2.1 Parts of a system
A computing system includes hardware, software, data, networks and the people who use them. At Ashcombe, staff use shared desktop computers at counters, laptops in offices and a library management system that holds member records. Public computers are used by visitors. Nadia learns that security depends on all these parts working together. A strong password policy on the management system means little if staff leave counter computers logged in while serving members, because the weakest interaction often decides the outcome rather than the strongest technical control.
2.2 Points of interaction
Nadia lists the points where staff interact with security: logging in at the start of shifts, locking screens when stepping away, handling member data requests, opening email and approving software updates. Each point demands attention and time. Adams and Sasse (1999) showed that users struggle with security mechanisms that do not fit their work, and that they are not the enemy but people trying to get their jobs done. Mapping these points helps Nadia see where the system asks too much of people and where design could help them.
2.3 A user journey
Nadia maps the journey of a counter assistant during a busy morning: log in, serve members, step away to fetch a book, return, answer a phone query and check email between members. She notes that locking the screen each time takes several seconds and a password re-entry. Assistants often leave screens unlocked because queues form quickly. She suggests a short automatic lock with tap-card unlocking. The map shows that the problem lies in the fit between task and control rather than in the attitude of staff.
Worked example
Nadia lists system parts, identifies interaction points and maps a counter assistant's journey to suggest tap-card unlocking.
Synthetic case. The journey is synthetic; Adams and Sasse (1999) is real.
Errors and limits
Journey maps simplify real work. Card readers cost money.
Exercises
- EX004 — Weakest interaction. Why does a strong password policy matter little in one case? Rubric: 3 = if counter computers stay logged in;; 2 = logged in;; 1 = vague;; 0 = none.
- EX005 — Adams and Sasse. What did Adams and Sasse (1999) show about users? Rubric: 3 = they are not the enemy and struggle with ill-fitting mechanisms;; 2 = fit;; 1 = careless;; 0 = none.
- EX006 — Suggested fix. What fix did Nadia suggest for unlocked screens? Rubric: 3 = short automatic lock with tap-card unlocking;; 2 = tap card;; 1 = longer passwords;; 0 = none.
Synthesis
Security lives at the points where people interact with systems, and fit with work matters most.
Continue studying — chapter 02 of 40
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