Establishing Design Criteria

Introduction: turning a problem into a clear target 🎯

students, in the Design Project and Practical Programme, one of the most important early steps is establishing design criteria. This is where a design idea stops being a vague thought and becomes a clear set of goals that can be tested and judged. In IB Design Technology HL, this matters because strong projects are not just creative; they are also focused, realistic, and measurable.

A designer first learns about the client, the target audience, and the end-user. Then, based on research and evidence, the designer writes design criteria. These criteria describe what the final product must do, how well it should work, and sometimes what limits it must follow. Good criteria help with modelling, testing, and development later in the project because they give a clear standard to compare against.

By the end of this lesson, students, you should be able to:

explain what design criteria are and why they matter,
use IB Design Technology HL reasoning to write strong criteria,
connect design criteria to the whole design project,
and show how evidence from research leads to better design decisions.

Think of design criteria like the rules and goals for building a custom backpack, a phone stand, or a school desk. Without them, the design process can become random. With them, every decision has a purpose 😊

What are design criteria?

Design criteria are the statements that define the success requirements for a design. They describe the features, performance, and qualities the product should have. In simple terms, they answer the question: What must this product achieve?

In IB Design Technology HL, design criteria should be based on research, not guesses. A good criterion comes from evidence gathered from the client, the target audience, the end-user, and existing products. For example, if a client needs a portable study lamp, research might show that students need lightweight products because they carry them between rooms. That evidence can become a criterion such as $\text{mass} \leq 1.5\,\text{kg}$.

Design criteria are different from design specifications, but the two are closely linked. Criteria are the broad standards of success, while specifications are often more detailed and technical. For example:

Criterion: the product must be easy to carry.
Specification: the product mass must be less than $2\,\text{kg}$ and have a handle width of at least $10\,\text{cm}$.

A strong set of criteria often includes these categories:

function,
user needs,
safety,
size and ergonomics,
materials,
aesthetics,
sustainability,
cost,
and manufacturability.

The key idea is that criteria help turn a general design brief into a plan that can actually be tested.

How design criteria are developed from research

The design process in the IB is evidence-based. That means students should not create design criteria before doing proper research. First, gather information from several sources:

the client’s needs and expectations,
the target audience’s preferences,
the end-user’s abilities and limitations,
market research on existing products,
and subject knowledge such as materials, mechanisms, or ergonomics.

After collecting information, the designer looks for patterns. For example, if a school wants a classroom storage box, the research might show that it must be easy to lift, fit under desks, and be strong enough for daily use. From that evidence, the designer writes criteria like:

the storage box must fit within $600\,\text{mm} \times 400\,\text{mm} \times 300\,\text{mm}$,
the handle must support a load of at least $15\,\text{N}$,
and the materials must withstand repeated use without visible cracking after $100$ cycles.

This shows an important IB principle: criteria should be specific, measurable, and linked to research. A vague statement like “the product should look nice” is not strong enough on its own, because “nice” is hard to measure. A better criterion might be “the product should use a colour scheme matching the client’s brand identity and include at least two contrasting colours for visibility.”

Evidence also helps avoid unrealistic ideas. If a student designs a product that looks impressive but cannot be manufactured in the school workshop, the design may fail in practice. Good criteria keep creativity realistic.

Writing strong criteria: the SMART idea in design thinking

A useful way to check criteria is to ask whether they are similar to the SMART approach: specific, measurable, achievable, relevant, and time-aware. In Design Technology, the exact wording may vary, but the logic is the same.

A strong criterion should be:

Specific: clearly states what is required,
Measurable: can be tested or checked,
Achievable: realistic with the available time, tools, and materials,
Relevant: linked to the client and user needs,
Evidence-based: supported by research.

Compare these two examples:

Weak criterion: “The chair should be comfortable.”

Stronger criterion: “The seat height should be $420\,\text{mm} \pm 20\,\text{mm}$ to suit the average desk height used by the target users.”

The second version is better because it can be measured and tested. It also connects directly to ergonomics, which is a major part of design projects.

Another example:

Weak criterion: “The product should be eco-friendly.”

Stronger criterion: “At least $60\%$ of the product’s material by mass should come from recycled or sustainably sourced materials, where available and appropriate for strength.”

This is better because it turns a general idea into a checkable target. It also shows that sustainable design often involves balancing environmental goals with performance and safety 🌱

Using design criteria in modelling, testing, and development

Design criteria are not just written at the start and then forgotten. They are used again and again throughout the project.

When making models, the designer can test whether a concept meets the criteria. For example, a cardboard prototype of a desk organiser may show whether pens fit properly or whether the angle is stable. If the model does not meet a criterion, the designer can improve the design.

During testing, the criteria become the benchmark. A test should check a specific criterion. For example:

Criterion: the phone stand must hold a device at an angle between $60^\circ$ and $70^\circ$.
Test: place a phone on the stand and measure the angle with a protractor.

Testing can be qualitative or quantitative. Quantitative tests use numbers, such as mass, height, angle, force, or time. Qualitative tests involve judgments, such as appearance or user feedback, but even these should be supported by evidence where possible.

In development, the designer improves the product based on test results. If a prototype fails to meet a criterion, the designer changes the design. For example, if a shelf bends too much under load, the designer may increase material thickness or change the support structure. The criteria act like a map that shows whether each version is moving in the right direction.

This is why strong criteria are so important in IB Design Technology HL: they connect the problem definition to the final solution.

Client, target audience, and end-user: why different viewpoints matter

A common mistake is to treat the client, target audience, and end-user as if they are all the same. In reality, they can be different.

The client is the person or organisation requesting the design.
The target audience is the group the design is aimed at.
The end-user is the person who will actually use the product.

For example, a school may be the client for a new classroom tool. The target audience might be teachers, but the end-users might be students. The design criteria need to reflect all three viewpoints. A teacher might want durability and easy cleaning, while students might want comfort and easy access.

This is why research matters. If students only listens to the client, the final product may not suit the end-user. If students only thinks about appearance, the product may not meet practical needs. Good criteria balance these different demands.

Here is a simple example:

Client need: the product should be low maintenance.
Target audience need: the product should be visually appealing to teenagers.
End-user need: the product should be easy to use with one hand.

A strong set of criteria might include durability, style, and one-handed operation. Each criterion should be connected to evidence.

Conclusion

Establishing design criteria is a foundation of the Design Project and Practical Programme. It transforms research into clear goals and gives the designer a way to judge success. In IB Design Technology HL, the best criteria are specific, measurable, realistic, and based on evidence from the client, target audience, and end-user.

students, if you remember one thing from this lesson, let it be this: design criteria are not just a list of wishes. They are the standards that guide modelling, testing, and development, helping a project move from idea to effective final product. Strong criteria make design decisions easier to justify and final products easier to evaluate ✅

Study Notes

Design criteria define the standards a product must meet.
They are based on research, not guesses.
Good criteria are specific, measurable, achievable, and relevant.
Criteria help the designer evaluate ideas, models, prototypes, and final products.
Criteria often include function, user needs, safety, size, ergonomics, materials, aesthetics, sustainability, cost, and manufacturability.
The client, target audience, and end-user may have different needs, and criteria should reflect all of them.
Quantitative criteria use numbers such as $\text{mass}$, $\text{height}$, $\text{angle}$, or $\text{force}$.
Qualitative criteria can include appearance or user experience, but should still be supported by evidence.
Design criteria guide modelling, testing, and development throughout the project.
Strong criteria make final evaluation more objective and more accurate.