Lesson video

Hello there, my name's Mrs. Taylor, and I'm really pleased you can be here.

Our lesson today is "Testing and modifications: textiles" and this is part of the "Iterative design: nature" unit.

The outcome, I can test and evaluate the manufactured prototype.

There are five keywords.

Evaluation, checking how good something is and how to make it better.

Design specification describes what a product has to do.

Destructive testing is testing that destroys the material or product.

Non-destructive testing is testing without destroying the material or product.

And modifications, making changes or adjustments to improve or alter a design.

There are three parts to the lesson today, evaluation against the design specification, testing, and future modifications.

Let's get started with evaluation against the design specification.

Once a prototype is complete, the product needs to be tested and evaluated.

To evaluate is to check how good something is and consider how to make it better.

No product is ever perfect, and further modifications can always be considered.

One way to evaluate a product is to evaluate it against the original design specification.

Designers evaluate against the design specification to ensure that the final product meets the required standards, functions as intended, and satisfies user needs.

It also supports continuous improvement and iteration as it provides insights for refining and modifying future designs.

Here we have a check for understanding.

What can we evaluate a final prototype against? Is it A, an existing product, B, a design specification, or C, initial design ideas? Pause the video and have a go.

Wonderful, let's check.

That's right, it's B, a design specification.

Well done.

The design specification describes what a design must have or do and is dictated by the research gathered.

It is written early in the design process, after research but before prototyping, to ensure the product meets user needs.

Sofia worked on the design opportunity of making herbs accessible to wheelchair users.

This is Sofia's design specification.

The user, the herb growing system must be suitable for wheelchair users.

And the justification for this, this is to ensure the user can use the product safely and efficiently.

Materials, the materials must be waterproof and suitable for cleaning.

The product will need to hold plants, which need watering, and therefore must be waterproof.

Function, the system must allow herbs to be grown from seeds and also as plants.

Some users will want to grow herbs from seeds and others will buy plants.

Sofia's design specification continues.

Aesthetics, the system must fit into a modern grey and silver kitchen theme because my user has a modern grey and silver kitchen theme.

The environment, the system must be sustainable.

My user is very conscious about the environment and would prefer not to cause any damage for future generations.

Safety, the system must be stable and not topple over.

Some plants grow taller than others.

Let's have a check for understanding.

What is the purpose of a design specification? Is it A, it provides step-by-step instructions for making the design, or B, it describes what a design must have or do, or C, it lists personal opinions about the design? Pause the video and have a go.

Wonderful, let's check.

That's right, it's B.

It describes what a design must have or do.

Well done.

Sofia has evaluated her prototype against her design specification by deciding whether she has met the specification points or not met them.

We can see here that user and materials have not been met, but function and aesthetics have been met.

The environment is not met, and safety, it has been met.

Sofia has explained why she thinks she has met and not met each point as part of her evaluation.

The herb growing system must be suitable for wheelchair users.

The product goes on the countertop so is more accessible from a wheelchair than a windowsill, but the top pocket was too high to reach safely.

The materials must be waterproof and suitable for cleaning.

The ripstop nylon is waterproof, but the MDF frame was not.

The system must allow herbs to be grown from seeds and also as plants.

The product can hold small potted seeds as well as larger plants.

And the evaluation against the design specification continues.

The system must fit into a modern grey and silver kitchen theme.

The ripstop nylon in grey fitted in well, but the MDF would have been better if it was also grey.

The system must be sustainable.

The MDF comes from a sustainable source, but the ripstop nylon does not.

The system must be stable and not topple over.

The product has a stable base with no way of toppling over.

We now move to task A, evaluate your final prototype against your design specification.

You could lay it out similar to the table below.

Pause the video and have a go.

Great, let's have a look at some of the answers you may have come up with.

The herb growing system must be suitable for wheelchair users has not been met.

The product goes on the countertop so is more accessible from a wheelchair than a windowsill, but the top pocket was too high to reach safely.

The materials must be waterproof and suitable for cleaning was not met.

The ripstop nylon is waterproof, but the MDF frame was not.

The system must allow herbs to be grown from seeds and also as plants, this was met.

The product can hold small potted seeds as well as larger plants.

Well done.

We now move to the second part of the lesson, testing.

Testing is another way to evaluate a final prototype.

There are two main types of testing, destructive and non-destructive.

Destructive is testing that destroys the material or product, and non-destructive is testing without destroying the material or product.

Destructive testing would be better suited during the design development and research stage of the design process.

And non-destructive testing is better suited for the end evaluation as it ensures the prototype will not get ruined.

Here we have a check for understanding.

What type of testing does not destroy the material or product? Is it A, destructive testing, B, procedural testing, C, non-destructive testing, or D, declarative testing? Pause the video and have a go.

Fantastic, let's check.

That's right, it's C, non-destructive testing.

Well done.

The designer must first decide what it is they need to test on their product.

Sofia has decided that she needs to test the accessibility of the top pocket.

Once she has decided on what she needs to test, she can then devise a way to carry out those tests.

Sofia has decided to test her herb planter in two ways, measure the planter height on different kitchen surfaces and observing her user using the product to see how they find using the planter.

We now move to task B.

Part 1, what testing will you do on your final prototype? And part 2, explain how you will carry out each of the tests.

Pause the video and have a go.

Wonderful, let's have a look at some of the answers you may have come up with.

Sofia says, "I need to test the accessibility of the top pocket on the herb planter." And she also says, "I will place the herb planter on the kitchen table, the kitchen counter, and the kitchen floor, and then measure the height of the top pocket in each location.

I will also observe my wheelchair user watering and harvesting the plants to assess which location would be most suitable." Well done.

The third part of the lesson is future modifications.

Future modifications are when the designer makes changes or adjustments to improve or alter a product.

The evaluation against the design specification and the testing are used to inform and justify future modifications to the product.

Justification is the reason or explanation for why something is done or believed to be right.

Designers need to ensure that any future modifications are justified based on the client's wants and needs.

Here we have a check for understanding.

Why is it important for designers to justify future modifications to their products? Is it A, to make random modifications that the designer prefers, or B, to ensure that changes align with the evaluation and testing results, or C, to avoid considering the research and testing done throughout the design process? Pause the video and have a go.

Fantastic, let's check.

That's right, it's B, to ensure that changes align with the evaluation and testing results.

Well done.

Sofia's evaluation against the design specification gave her some points that could be used for future modifications to her product.

These were, the product is not as waterproof as it needs to be to protect it from the watering of the herbs.

The materials are not all sustainably sourced.

Sofia now needs to consider ways to improve her product using these points from her evaluation and testing.

She could present these ideas in any of the following ways, or a combination of them, an explanation of modifications, a sketched drawing of a modification, CAD drawing of modifications, or a model of a prototype with modifications.

We now move to task C.

Part 1, write your own success criteria for evaluating, testing, justifying, and carrying out future modifications on your product.

And part 2, use your success criteria for evaluating, testing, justifying, and carrying out future modifications on your product.

Pause the video and have a go.

Wonderful, let's have a look at some of the answers you may have come up with.

For part 1, you may have included, evaluate final prototype against design specification to say whether the points have been met or not, and explain how they have been met or not.

Decide on what needs to be tested.

Decide on how to carry out the tests.

Use testing and evaluation against the design specification results to pick out what could be improved.

Present modifications in the chosen way.

And part 2, you can use this as a checklist, as we can see here.

Well done.

We now have a summary of our learning today.

Once a prototype is complete, the product needs to be tested and evaluated.

To evaluate is to check how good something is and consider how to make it better.

Designers evaluate against the design specification to ensure that the final product meets the required standards, functions as intended, and satisfies user needs.

Testing can also be used as a way to evaluate a final prototype.

The evaluation against the design specification and the testing are used to inform and justify future modifications to the product.

Thank you for joining me today, and well done.