Lesson video

Hello, thank you for joining me for your design and technology lesson.

My name is Mrs. Conway, and I will be guiding you through your learning today.

So today's lesson outcome is, I can determine and justify the size of my design.

So we've got our final design and we're now starting to think about the size of it and also think such as proportion, which we're gonna be looking at closer as we work through this lesson.

These are our keywords for the lesson.

Specification, justification, proportion, dimensions, and scale.

I'll go into each one of these as we go through the lesson today.

So we're gonna start off with looking at design decisions.

Now, design development is about constantly seeking ways to improve our design ideas.

And once a designer has decided which design has the most potential, they're gonna then take that idea forward in development to eventually manufacture it.

But it'll still need some final tweaks as it goes into almost like the next stage of development.

Now a designer can evaluate their design against their original design specification to help them decide which design to take forward, and also to be able to justify those design decisions that they are making.

So let's just do a quick check for understanding on that.

What can a designer evaluate their design against? Is it A, a design specification, B, an existing product, or C, someone else's design ideas? Pause the video here if you'd like to take a moment just to think about that.

Okay, and the correct answer was A.

A design specification.

So a designer can evaluate their design ideas against their design specification to be able to justify their design decisions.

Now let's just remind ourselves of a design specification.

A design specification describes what a design must have or do, and is dictated by the research that has been gathered.

And to justify design decisions is to give a reason or explanation for those decisions, and we must be constantly doing that as we work through any kind of NEA work or any kind of design process work.

Now, Laura has been developing ideas for the design opportunity of making the herbs accessible to wheelchair users.

Now when she started her design process, Laura did some research, which she then followed with a design specification, and she used the research to help her to write this.

This is Laura's design specification.

Now I won't go through each of the points, but you can see that she has, for example, user.

Her then specification points are under that kind of concept of user is the herb growing system must be suitable for wheelchair users.

And she's justified that statement by saying that this is to ensure the user can use the product safely and efficiently.

So even when she was carrying out her design specification, she was still justifying the points that she made by referring to the research.

Feel free to pause the video here if you'd like to read this through in a little bit more detail.

And this was the rest of Laura's design specification.

Again, you'll notice you've still got those three headings and you've also got the subheading points down on the left-hand side, followed by her specification points and then her justification for each of those points.

Again, feel free to pause the video here just to read this through in a bit more detail if you'd like.

So let's just do a quick check for understanding on that.

What is the purpose of a design specification? Is it A, it provides step-by-step instructions for making the design.

Is it B, it describes what a design must have or do.

Or is it C, it lists personal opinions about the design.

Pause the video here if you'd like to take a quick moment to think about that.

And the answer was B.

So the purpose of a design specification is it describes what a design must have or do.

So let's have a look at Laura's most recent design developments.

This was her most recent idea, and she's just explained why she likes this.

"I like the step system that goes onto the kitchen work surface, so I'm going to evaluate this against my design specification to see if it meets the points on it." So, Laura has decided that she likes this design, but she wants to check that she's correct to like it, that it's actually going to meet all the points that she has stated on her design specification that the design must have or do.

Now to do this, Laura has completed the table below of whether she thinks she has met her design specification points or not met them.

So these are the design specification points that we've just shown you.

All I've done here, though, is the justification column has been removed, but the same points are still here.

You've still got the same subheadings and the same specification points.

So if I just point out to your user, again, it says the herb growing system must be suitable for wheelchair users.

Now what Laura is going to do is she's going to go through each one of these in turn and either give them simply a tick to say she has met that point or a cross to say that she has not met that point.

And here, she's done that.

So she feels she has met her specification point about user, but not materials.

So she thinks the materials are not waterproof and not suitable for cleaning in the design she's got at the moment.

So she needs to consider that.

She thinks she has met function, but she hasn't met aesthetics.

She feels, at the moment, it doesn't quite fit into the modern grey and silver kitchen theme that she was aiming for.

And again, she'll need to do some further developments on that.

But she feels she has met the environment consideration and also the safety consideration of it not toppling over.

Now by evaluating her design against her design specification, Laura has now justified her decision to take the design forward.

The majority of her specification points were met, but she just needs to do some further development points on the ones that weren't met, just to make sure that she's hitting all or as many of those specification points as possible.

Now she's also been able to review whether she still needs to make any changes or improvements to her design idea by doing that.

And here's what she says.

"I feel that this design meets enough of my design specification points for me to take it through to further development, but I still need to do some improvements to make it and meet more of the design specification points." Now she's completely correct.

As we said, she hadn't met two of her specification points, so she must do further development to make sure that she can meet those last remaining two.

So let's just do a quick check for understanding on that.

What is it called when an explanation or reason is given for design decisions? Is it A, estimation, B, observation, or C, justification? Again, feel free to pause the video here just to take a moment to think about your answer.

How did you get on? The correct answer was C.

It's the justification.

So that is the reason or explanation given for making the design decisions that you have.

Now, Laura now needs to justify and explain why she thinks she has either met or not met each of those points on the design specification that she went through.

And here, she's done that.

Now this table is the same as before, but instead of the column that says met or not met, that's just been removed and replaced with justification.

But the specification points are the same still.

So if we take the first one, this was our user specification point, the herb growing system must be suitable for wheelchair users.

Now if you remember, Laura has said that she feels she has met that point.

So what she's now doing here is just justifying how she thinks she has met that point.

So she said the design goes on the countertop, so is more accessible from a wheelchair than a windowsill.

Now that's because Laura is trying to decide between two ideas.

One that went on a windowsill and one that went on a countertop.

And she has said that she feels the one that goes on the countertop is more accessible for wheelchair access, which means that it meets that specification point.

Now she said under the materials that, actually, she didn't feel she'd met this point, the materials must be waterproof and suitable for cleaning.

Now again, she's justified and explained why she thinks she hasn't met that.

I am making my design out of paper and board, so will need to consider how to make this waterproof.

So she's pointed out quite rightly that, actually, she's making this out of paper and board, which aren't naturally the most waterproof materials.

So she'll need to take some consideration into how she's going to protect those materials from the water when there could be a little bit of dripping from the plants.

Again, if you'd like to read these through in a little bit more detail, feel free to pause the video here to do that.

And this is the remainder of Laura's specification with her justification points.

Again, if you'd like to read through in a little bit more detail, feel free to pause the video to do so.

Okay.

So it's now gonna be over to you to have a go at a task.

The first task is to evaluate your chosen design against your design specification so as to help you justify your design decisions.

Your second task is to consider how your design still needs to be improved, and you can lay it out quite similar to the table below if you'd like to do so.

So while you are evaluating your chosen design ideas, you'll need to get your original design specification to put your design specification points into the left-hand column.

Then you are simply going to tick or cross to say whether or not you feel you have met or not met each of those points.

And the last column, the justification column, is where you explain and justify why you think you have met that specification point or why you think you have not met that design specification point, and what you might still need to consider to improve that.

Now pause the video here to have a go at this task, and good luck.

All right, how did you get on? So let's have a look at a completed evaluation against a design specification.

Now this is Laura's, and we've already had a brief little look at Laura's, but we can look at it in a little bit more detail here.

So you can see in the left-hand column, she has copied out her original specification points from her design specification.

She has then done in the middle column whether she feels she has met or not met those points with a simple tick or cross.

And then in the last column, it's her justification column.

So this is where she has explained why she thinks she has met that point or why she thinks she hasn't met that point.

And also thinking about what further developments she may need to do to make sure she can meet those points.

Just as before, if you would like to pause the video to look at this in a little bit more detail, feel free to do so.

Now yours will be different to Laura's and you'll have your own specification points, your own decisions of whether or not you've met them, and obviously, completely different justifications to everyone around you as well.

That's fine.

Just compare it to mine.

And do you think you've got enough detail or do you think you've explained or justified each of those decisions correctly? Right.

So let's move on.

We're gonna now look at proportion and size.

Now when designing, it's important to consider proportion, size, and scale of a design.

The proportion of a design refers to the balanced relationship between different parts of a product and altering those proportions can actually change it aesthetically, as well as functionally, and even ergonomically as well.

So changing the proportion can actually make a really big difference, but it's quite often forgotten.

We often think about form and we often think about aesthetics, but actually, small changes in something like the proportion can make a really big difference.

Getting the right proportion and size of a product is important.

Let's have a look at an example as to why it's important.

Now hairbrush one has a very small handle.

Now if you've used a hairbrush, you'll realise that, actually, that will make it quite uncomfortable, as well as actually being quite difficult to hold.

It could actually then result in repeatedly dropping the hairbrush when using it, 'cause there just really isn't much to actually grab hold of.

So it could fall out of the hand very easily once you actually start brushing your hair.

Now hairbrush two, you can see the handle is longer.

It's the same kind of shape, but the proportion of the length of it has altered slightly.

Now by changing the proportion of the handle and making it that slightly bit longer, it's got a more now balanced product.

So the weighting of the product is a little bit better balanced for use, as well as it being more comfortable.

And also, it's just now easier to hold and to actually use.

So that's changed the aesthetics, but it's also changed the ergonomics and the function of the hairbrush just by changing the proportion of the handle ever so slightly.

So let's just do a quick check for understanding on that.

What is proportion? Is it A, a method for calculating the volume of objects, B, a type of measurement used only in geometry, or C, a balanced relationship between different parts? Pause the video here just to take a moment to think about that.

How did you get on? The correct answer was a balanced relationship between different parts.

Well done if you got that right.

Now if we go back to Laura, Laura is worried that her design is just too big for a kitchen countertop and will actually just take up too much space.

And kitchen countertop space is often needed to prepare food.

So this is the side view of Laura's design.

And you can see, she's got actually quite a few steps for this.

If you look at the 3D version, again, quite a few steps, but it's also quite a wide product.

Now this would actually store a large amount of herbs, but the question is, do we need to actually store that amount of herbs or could we make it smaller and help it to take up less space on that kitchen countertop? Now Laura's decided, considering all of that, she needs to alter the proportions and the size of the product.

But to do this, she'll need to gather some external data to help plan her sizes correctly.

So what data do you think Laura needs? If we're thinking about measurements, what measurements or sizes of things would she need to consider when changing the proportion and size of her product? Feel free just to take a moment to have a think about that.

Okay.

So what ideas did you come up with for what kind of data Laura will need to gather? So this is the data that Laura decided she needed.

She needed to know the depth of the average kitchen countertop, and she managed to find that data at around 600 to 650 millimetres.

That's the average.

She also realised that she actually needed to find out a little bit about plant pot sizes, and she found that the height of a one litre plant pot was 110 millimetres, and that's gonna affect the actual height of each step.

And she also found out the diameter of a one litre plant pot as well, which is 100 millimetres.

Now by knowing all of that, she's gonna be able to make much more informed decisions about the size and proportions of her product.

It's going to allow her to work out the correct dimensions that she needs and to make sure that she is going to be able to fit these little plant pots on.

And it's not gonna take too much space on an average kitchen countertop.

So when we're talking about dimensions then, I just mentioned, Laura is now gonna be able to work out her dimensions, but what are dimensions? So the dimensions are the sizes of objects or components, and dimensions are calculated when designing.

And this is based on research gathered such as anthropometric measurements, and also the external data such as the ones we just gathered then.

And dimensions are commonly represented in millimetres when we are working in design and technology.

Now this allows for a greater mm accuracy when we are manufacturing.

Okay, so let's just do a quick check for understanding on dimensions.

What do dimensions describe? Is it A, the weight of an object, B, the size of an object, or C, the colour of an object? Pause the video here just to take a moment to think about this.

The answer, it is the B, the size of an object.

Well done if you got that right.

Now here, Laura has altered the proportions and size of her product, and drawn out a new sketch with those dimensions added on.

Now she's altered the proportions and size of her product by doing the following things.

She's given it much less steps.

She's now gone to three steps, feeling that that's plenty.

She's also means that by reducing the amount of steps, it's not as deep.

So she's made the overall product not as deep, which means it won't take up as much space on the actual kitchen countertop.

She's also lowered the step height.

She's realised that each step doesn't need to be as high as she thought it did, and actually, it can be a lot more kind of gradual.

So again, it's not gonna be standing as high either.

And she's also made it narrower.

She's decided that she only really needs to fit two plant pots per step.

And so she's worked that out using the diameter of the plant pots to be able to decide how many she can fit on each step, and that will be plenty.

So she's made it narrower overall, again, saving on that kitchen countertop workspace.

All right, time for you guys to have a go.

You're going to gather any external data you need to work out the proportions and size of your product.

So you'll need to take a little moment to kind of think about this.

What external data do you specifically need for your product? Is there something you need to find out? If you are storing something in your product, do you need to find out the typical measurements of that something that you are planning to be stored in it, for example? You are then going to sketch out your final design with any changes in proportions and also include your dimensions in millimetres.

So this is the time to make any kind of last changes to things such as the proportion and size of your product, but it's also a time to actually make decisions about the dimensions.

So you'll need to be finding out that external data to be able to make these decisions.

Okay.

Pause the video here and good luck with this task.

Right.

How did you get on? Now that was quite a big task for you to do.

So your first thing was to gather any external data you need to work out the proportions and size of your product.

And Laura gathered this data, if you remember, she gathered the depth of the average kitchen countertop, she also found out the height of one litre plant pot, and she also found out the diameter of a one litre plant pot as well.

And all of the external data was then there to help her to work out the size and proportions of her final product.

So she's now sure and confident that her herb planter will actually fit into the planned location that she intends it to be used in.

The second part of the task was then to work out the proportions, but also the dimensions of the product.

And remember, you were meant to be doing this in millimetres, and we work in those millimetres for accuracy.

Now you see, Laura here has done actually a quick 2D view sketch of her product.

And actually, it manages to include a lot of the different dimensions.

Now this drawing is just her working out what each of these sizes is going to actually be.

Again, using that external data to help her.

And she's explained it here.

"I have drawn a side view of my design in 2D to show all of the dimensions, including the size of the steps.

I used the data I had gathered about the size of the plant pots to work out each step size and this then helped me work out the overall size of the product." Of course, yours is going to be completely different.

So just kind of look at yours and question, did you get all the external data that you needed? Are those dimensions based on the external data? Hopefully, you didn't ignore it.

And are you happy with all of the dimensions? Did the proportion of the product look right aesthetically? Do you think it'll function correctly? And if the user interacts with it, do you think it's also ergonomic as well? Laura has also included a 3D sketch of her proportions because the 2D sketch didn't quite include all of those proportions that she needed.

For example, it wasn't able to show the width of the object as well.

So she's just explained, "I've also drawn the idea in 3D so that I can show all of the dimensions that couldn't be seen in the 2D sketch.

I've done my dimensions in millimetres so I can manufacture it as accurately as possible.

So again, she's thought about doing it in millimetres as well.

Right, lastly then, we're going to just look at scale.

Now when drawing final designs or making prototypes, designers often have to work to scale.

So what is scale? Scale is a ratio of full size, and you may have come across it in math lessons.

Scale is used in design and prototyping to represent objects at a different size than their actual dimensions.

And what this does is it helps designers create accurate drawings and prototypes that are easier to work with.

Let's just do a quick check for understanding on that then.

What would a designer use to represent objects a different size than their actual dimensions? Is it A, proportion, B, scale, or C, dimension? Pause the video here if you'd like to take a moment to think about that.

And the answer was B, it's scale.

Well done if you got that right.

Now there are standardised scales that are used by designers, engineers, and also architects.

And these are conventional ratios that are international.

And this way, everyone knows how to interpret scale drawings regardless of where they live in the world.

It's like an agreement that we're all going to use the same kind of system.

Now some common standardised scales in product design are 1:1, 1:2, 2:1, and 1:5.

There are more than that.

These are just some examples.

So let's look at these ratios in a little bit more detail.

Designers have to choose the most appropriate scale to use when drawing or making prototypes.

Now if we look at the one-to-two scale, for example, a one-to-two scale means the drawing or model is half the size of the real object.

For example, if a car is four metres long in real life, a one-to-two scale model would be a two metre long model because it is half the size.

If the numbers are the other way around, however, and we look at a two-to-one scale, you can hopefully guess that this means the drawing or model is twice the size of the actual object.

So if a phone is 10 centimetres in real life, a two-to-one scale drawing would show it as 20 centimetres, as it is twice the size.

Let's just do a quick check for understanding on that.

If something is drawn five times smaller than it is, what scale would this be? Would it be A, 1:50, B, 5:1, or C, 1:5? Pause the video here just to take a moment to think about that.

And the answer, it's 1:5.

So if something is drawn five times smaller than it actually is, it would be a 1:5 scale.

Really well done if you got that right.

Now prototypes can also be made to scale.

It's not always appropriate to make a full-sized prototype and various factors need to be considered when deciding whether or not to make a full-sized prototype or at a scale prototype.

Now the factors that need to be considered are, the manufacturing space that you have to actually work in, considering the amount of people that are also manufacturing in the same space.

Also, the storage space that you have whilst manufacturing that product.

The cost of materials is important as well.

If the materials that you're using has a very high cost more than necessarily you have as a budget, then you might benefit from making it smaller to reduce the cost of those materials.

And also, of course, time to build.

If you have a limited amount of time, are you going to be able to make it full sized in the time that you have? Would you, again, benefit from making a smaller prototype to ensure that it is finished within the appropriate amount of time? And lastly, the sustainable use of materials.

Obviously, we should always be thinking sustainably as designers, but are we using the materials in the most sustainable way? Again, if we made it smaller, we could save our materials.

And would that be a better decision, considering the materials we're choosing to use? Now making a prototype in a smaller scale will still allow for the product to be manufactured and also tested.

But before making a prototype, designers should just ask themselves, do I need to actually make this prototype full sized for it to be effective? If the answer is yes, then make it full sized, if you haven't got any of those restrictions we've just mentioned on the previous slide.

But if, however, you think it's not necessary and some of those points that we've just gone through would actually be a bit of a problem, then consider making it to scale.

So here's your task.

Consider and decide on the scale that you will make your final prototype.

You'll need to look at your final design and your chosen dimensions to help you decide this.

Once you've made those decisions, you need to explain and justify why you decided to use the scale that you have.

Pause the video here to have a go at this task, and good luck.

Right.

How did you get on? You've had some really big decisions to make on your product today and your final design, and your final prototype.

So it's been quite hard work for you.

Hopefully, you were able to make a few more decisions on the scale side.

So I asked you to consider and decide on the scale that you will make your final prototype, and you needed to look back at your final design and also your decided dimensions to help you decide this.

Now, Laura has said this, "I have drawn my 2D sketch in 1:2 scale." So she's actually drawn her sketch half the size of what it will actually be.

And she said, "Meaning it is half the size of my actual product so that it could fit onto an A4 piece of paper." Now that's really clever of her to work that out and to actually make sure that it fits onto a piece of paper.

However, she then said, "I've decided to make my prototype 1:1 scale." Now if you remember, 1:1 scale means actual life-size scale.

She's decided to make it to its full size.

Now the second part of the task was to explain and justify why you decided to use the scale that you have.

So, Laura now needs to do that.

And Laura has said, "I decided to use 1:1 scale for my final prototype as it is not a big product anyway.

I will have enough space to make and store it in the classroom, and will not use up too many materials due to it being quite small." So that decision completely works for Laura.

It's not gonna be too much of a problem to make it full sized.

Now of course, you're gonna have different answers to Laura, and hopefully you've been able to work out your own scale, and you're happy with that decision.

And then your second task, of course, is to justify it.

So as long as you've explained your reasons as to why you've decided to either make it to scale and to what scale, or whether or not you are keeping it 1:1 scale and full sized, as long as, again, you've given your reasons as to why you think that's a suitable thing to do.

So today, we've looked at proportions and scale.

A designer can evaluate their design against their original design specification to help them decide which design to take forward and also to justify their design decisions.

The proportion of a design refers to the balanced relationship between different parts of a product.

And we looked at a hairbrush example just to help us understand that.

And altering the proportions of a design can actually change it quite significantly, even though they're usually just quite small changes, and they can change it aesthetically, as well as functionally, and also ergonomically as well.

And the last thing we looked at was scale, and scale is used in design, but also prototyping as well to represent objects at a different size than their actual dimensions.

Well done for the lesson today.

There was lots to go through.

And as I said, there was lots for you to do today as well, and lots of decisions to make as you're nearing the end of the design process.

So, well done.

Thanks for joining me today and I will see you soon.