When a team plans a new system, it first needs facts about how the current one works. A data-collection method is the way those facts are gathered. Questions ask you to name a method, describe it, and justify the choice for a particular case.
This lesson follows extracting user requirements and sits inside the ICT applications and system lifecycle module.
What are the four common methods?
| Method | What it is | Good for | Weakness |
|---|---|---|---|
| Interview | Questions asked face to face, with follow-ups | Detailed opinions from a few people | Slow, and one person’s view may be biased |
| Questionnaire | Same written questions to many people | Many answers quickly, easy to count | People skip questions; no follow-up |
| Observation | Watching the system in use | Seeing what people really do | People may behave differently when watched; takes time |
| Document review | Reading forms, reports and records | Seeing exactly what data is kept | Does not show why things are done |
How do you choose?
Ask three questions about the case:
- How many people are involved? Many people suggests a questionnaire; few suggests interviews.
- What kind of fact is needed? Opinions suit interviews; actual behaviour suits observation; data fields suit document review.
- How much time is there? Observation and interviews take longer.
Often a combination works well, and you can say so if you give a reason for each.
Worked example
Invented case: Kedai Buku Mawar wants an ordering system. There are three staff and about 200 regular customers. Orders are currently written in a notebook.
Step 1, staff: only three people, and their daily habits matter. Use observation for one day, then a short interview with each.
Step 2, customers: 200 people, and the shop only needs simple preferences, such as whether they would use an order form. Use a questionnaire.
Step 3, current data: the shop needs to know what details are recorded now. Use document review of the notebook pages.
Step 4, justify: “Observation shows how staff really take orders, and the notebook shows exactly which details are recorded, so the new form can include them.”
The mistake to watch for
A common slip is to give a definition and a stock advantage that ignores the case.
Mistaken answer: “Use a questionnaire because it is cheap and quick.”
For a shop with three staff and an unclear process, this skips the detail needed.
The correction is to use numbers and details from the case: “With only three staff, interviews are practical and allow follow-up questions about problems.”
Check yourself
1. A school (invented) wants opinions from 800 pupils on a new timetable app. Which method is the most suitable, and why?
Show answer
A questionnaire: it reaches many people quickly and answers are easy to count. Interviewing 800 pupils would take too long.
2. Which method would show that cashiers skip a step in the current process?
Show answer
Observation, because it shows what people actually do rather than what they say they do.
3. Name one weakness of document review.
Show answer
It shows what is recorded but not why. For example, a form may have a field that nobody uses.
Where this leads next
With facts collected, the next design step is designing an input form. The ICT practical task and evidence checker helps you keep your evidence tidy.
If you tend to write the right definitions in the wrong place, our team’s online one-to-one ICT tuition can help you match methods to scenarios.