Lesson video

Hello! My name's Mrs. Taylor.

And I'm so pleased you can be here to join me for our lesson today.

Our lesson today, is Testing and Modifications: Polymers and Timbers, and this is part of the Iterative Design: Nature unit.

The outcome.

I can test and evaluate the manufactured prototype.

There are five key words in this lesson.

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

Design specification, which describes what a product has to do.

Destructive testing, this is testing that destroys the material or product.

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

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

There are three learning cycles in this lesson.

Evaluation against the design specification, testing, and future modifications.

Let's begin 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 prototype 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.

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

This is Aisha's design specification.

This is Aisha's design specification.

We can see the details below.

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

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

The materials must be waterproof and suitable for cleaning.

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

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

And the justification for this is that some users will want to grow herbs from seeds, and others will buy plants.

Aisha's design specification continues and she states aesthetics, the system must fit into a modern grey and silver kitchen theme.

The justification for this, my user has a modern grey and silver kitchen theme.

The environment, the system must be sustainable.

And the justification for this is that 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.

And the justification for this is that some plants grow taller than others.

Here we 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! Aisha has evaluated her prototype against the design specification by deciding whether she has met the specification points, or not met them.

We can see here that she thinks the user and materials have not been met, but the function has been met.

Aesthetics has not been met, but the environment has been met, and safety has not been met.

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

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

And the explanation, the lower shelf is accessible but the top one is out of reach for a wheelchair user.

The materials must be waterproof and suitable for cleaning.

And the explanation for this, the MDF is not waterproof.

It was splashed when watering the herbs, but also got wet as the kitchen counter is next to the sink.

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

The explanation for this one, the product can hold small potted seeds as well as larger plants.

Her evaluation against the design specification continues.

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

The explanation here, the MDF would've looked much better if it had been painted to match the kitchen.

The system must be sustainable.

And the explanation, MDF is from a sustainable source.

The system must be stable and not topple over.

And the explanation, the product is not very stable.

The centre pole fits well into the base, but the shelves wobble.

Here we have Task A.

Evaluate your final prototype against your design specification.

You could lay this out similar to the table below.

Pause the video and have a go.

Wonderful! 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, because the lower shelf is accessible but the top one is out of reach for a wheelchair user.

The materials must be waterproof and suitable for cleaning, has not been met.

The MDF is not waterproof.

It was splashed when watering the herbs, but also got wet as the kitchen counter is next to the sink.

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

That has been met.

And the justification, the product can hold small potted seeds, as well as larger plants.

Well done! We're now going to move to the second learning cycle, 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.

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.

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.

Wonderful! 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.

Aisha has decided that she needs to test the top shelf accessibility.

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

Aisha has decided to test her herb planter in two ways.

Measuring the height of the top shelf when located on different kitchen surfaces, such as the floor and table.

And observing her user using the product to see how they find using the planter.

Task B.

Part one.

What testing will you do on your final product? And part two.

Explain how you'll carry out each of the tests.

Pause the video and have a go.

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

Aisha says, "I need to test the accessibility of the top shelf of the planter.

I will place the planter on different surfaces in the kitchen and measure the height of the top shelf.

I will also observe my wheelchair user watering and harvesting the plants to assess the accessibility." Well done! We now move to the third part of our lesson, 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 in their products? Is it A, to make random modifications that the designer prefers, 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.

Wonderful! Let's check.

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

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

These were, the MDF is not waterproof.

It was splashed when watering the herbs, but also got wet as the kitchen counter is next to the sink.

The product is not very stable.

The centre pole fits well into the base, but the shelves wobble.

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

She could present these ideas as any of the following, or a combination of them.

An explanation of modifications, sketched drawing of a modification, CAD drawing of modifications, or a model of a prototype with modifications.

Task C.

Part one.

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

And part two.

Use your success criteria for evaluating, testing, justifying and carrying out future modifications on your product.

Pause the video and have a go.

Fantastic! Let's have a look at some of the answers you may have come up with.

For part one, you may have said, evaluate the final prototype against the design specification to say whether the points have been met or not met.

explain how they have been met or not, decide on what needs to be tested, decide on how to carry out the tests, and use testing and evaluation against the design specification results to pick out what could be improved, present future modifications in a chosen way.

And for part two, you can use this success criteria as a checklist, as can be seen 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.

Well done, and thank you for joining me today!.