Investigation, primary and secondary data

Welcome to Design Detective Work!

Before a designer even picks up a pencil to sketch, they have to become a bit of a detective. You can't design a great product if you don't know who you are making it for or what problem you are trying to solve. In this chapter, we explore Investigation—the process of gathering primary and secondary data to make sure your final design is a success. Don't worry if this seems like a lot of information at first; we will break it down into simple steps!

1. Primary vs. Secondary Data: What's the Difference?

In the world of Design and Technology, "data" is just a fancy word for "information." Designers use two main types:

Primary Data: This is information you find out yourself, first-hand. It is brand new information that didn't exist until you went looking for it.
Example: You interview your grandma to find out why her kettle is hard to use.

Secondary Data: This is information that already exists. Someone else has already done the work, and you are just looking it up.
Example: You look up the height of an average kitchen counter on the internet.

A Simple Analogy:
Imagine you want to know if a swimming pool is cold.
- Primary Research: You stick your toe in the water. You felt it yourself!
- Secondary Research: You read a sign on the wall that says "Pool Temperature: 25°C." You are trusting someone else's measurement.

Quick Review: Data Types

Primary: Interviews, Questionnaires, Focus Groups, Product Analysis (hands-on).
Secondary: Internet research, Books, Magazines, Government reports.

2. Primary Research Techniques

To get the best primary data, designers use specific methods to talk to their client (the person paying for the product) and the user (the person who will actually use it).

Interviews: One-on-one conversations. These are great for getting detailed, personal opinions.
Questionnaires: A list of questions sent to many people. This is useful for getting lots of quantitative data (numbers and facts).
Focus Groups: A small group of people who sit down to discuss a product. This helps you see how different people might disagree on a design feature.
Human Factors and Ergonomics: This is the study of how people interact with products. Ergonomics is all about making products comfortable and easy to use. For example, the "squishy" grip on a pen is an ergonomic feature.

Did you know?
Ergonomics isn't just about comfort; it's about safety too! If a car dashboard is designed poorly, it might take a driver too long to find the brake button, which could be dangerous.

3. Anthropometrics and the "Power of Percentiles"

Anthropometrics is a big word that just means measuring people. Designers use charts of body measurements (hand length, sitting height, etc.) to make sure their products fit the human body.

Percentiles help us understand where a person fits compared to the rest of the population. In the exam, you need to know about the 5th to 95th percentile rule.

Imagine 100 people standing in a line from shortest to tallest:
- The 5th percentile is the very short person at the start of the line.
- The 50th percentile is the average person in the middle.
- The 95th percentile is the very tall person at the end of the line.

The Golden Rule: Most designers try to design for the "middle 90%" of people. This means they aim to fit everyone from the 5th percentile up to the 95th percentile. We usually ignore the very, very tiny and the very, very huge because it's too expensive to make one product fit absolutely everyone.

Math Link:
When you collect survey data, you might use a frequency table to show how many people chose a certain answer. For example:
\( \text{Total Respondents} = 50 \)
\( \text{People who liked Blue} = 25 \)
\( \text{Percentage} = (\frac{25}{50}) \times 100 = 50\% \)

4. Secondary Research: Learning from Others

Sometimes you don't need to reinvent the wheel. You can learn a lot from Product Analysis.

Product Analysis and Evaluation: This involves looking at existing products and asking:
- What materials did they use?
- How was it made?
- Why does it look that way?
- What are its strengths and weaknesses?

By evaluating existing products, you can find "gaps in the market"—things that other designers haven't thought of yet!

5. The Design Brief and Specification

Once you've done your research, you need to write down what you've found. This is done through two documents:

1. The Design Brief: A short statement that explains the problem you are going to solve. It is usually quite open.
Example: "Design a way for elderly people to garden without bending down."

2. The Manufacturing Specification: This is a detailed "to-do list" for your product. It contains specific performance criteria that the product must meet.
Example: "The product must weigh less than 2kg," or "The product must be made from recycled plastic."

Common Mistake to Avoid:
Don't make your design brief too specific! If you say "I will make a wooden chair with four legs," you've already decided what the answer is before you've finished your research. Keep the brief broad and let the research guide the specification.

6. Modifying the Brief

Sometimes, your research might show that your original idea won't work. For example, you might realize your "garden seat" is actually better used as a "tool caddy."
Don't worry! Real designers modify their brief all the time. This is part of the iterative design process—where you constantly test, learn, and change your ideas to make them better.

Section Summary: Key Takeaways

- Primary data is new (Interviews); Secondary data is existing (Internet).
- Ergonomics is about comfort/use; Anthropometrics is about body measurements.
- Aim for the 5th to 95th percentile to fit most people.
- The Design Brief is the goal; the Specification is the detailed set of rules.
- Research should always happen before you start making!