Lesson video

Hello, my name's Mr. Davidson.

You made a great choice in learning about databases with me today.

The title for today's lesson is Yes or No Questions from the unit, Organising Data Using Databases.

Some of this lesson will require you to think about questions carefully and think what answers you will give.

Take your time with them, but I know that you'll be able to do this really well.

By the end of today's lesson, you are going to be able to create questions that have yes or no answers.

There's going to be two key words that you're gonna see throughout the lesson today.

The first key word is object, which we're going to use as a word for something that is uniquely identifiable and has attributes.

So something that we can recognise and something that has properties that we can describe.

An attribute is also a word or a phrase that can be used to describe an object.

So we see lots of different attributes all around us in our everyday lives, such as an object's colour, its size, its price, and we sometimes refer to these things as properties.

Look out for them throughout the rest of the lesson.

I've split the lesson into two parts.

Let's start with the first, which is where we're going to identify questions with yes-no answers.

We all know that questions are very important in our lives.

We use questions to find things out.

We ask questions to find out properties of what we want to know, and we get someone to tell us.

Now good questions are hard to decide upon, especially when we're using them for computer data.

We have to be very careful about how we frame those questions.

Let's practise with some examples.

Andeep is gonna ask you the following questions and I want you to think about what answers you would give.

The first question is, "When do you eat breakfast?" Secondly, "How do you get to school each morning?" And the last question, "Is it raining?" Now with those questions, we could have got a range of answers depending on who was asking the question, who was responding, what time of day, where they are, and so on and so forth.

It's not always easy to expect certain answers.

Let's try that with a few more.

What is your favourite food? Is a parrot a bird? Are the walls in the classroom pink? So as I mentioned, you are going to give different answers and different people are going to give a range of answers as well.

Andeep asked, "What is your favourite food" to Jacob.

He responded that he really liked salad with lots of tomatoes.

Now, when he asked that to Jacob, he might have asked it to other people and they would've given a load of different answers.

What we have there with Andeep's question is something called an open-ended question.

Open-ended questions mean you can give an opinion or add more detail.

There's not specific answers that you can give, and we use the word elaborate, which means you can keep talking about the subject in more detail to answer the question.

Importantly though, sometimes we can have questions that aren't open-ended.

Those type of questions can only be answered with the response yes or no.

So think back to our question, "Is it raining?" Your answer would probably reflect whether it was raining outside when you are watching this video.

So as we ask, "Is it raining?" And as Andeep asks, "Is it raining?" Really there are only two answers.

It is raining or it's not.

Jacob in this case, looks out, sees the sun, no rain, and his response is no.

Jacob doesn't really need to keep explaining the answer because it's a closed question.

We only give him the chance to provide certain answers.

So let's check you've understood that.

I've given you a question there.

What are you having for lunch today? Now you can answer this question with a yes or a no answer.

Is that true or is it false? What do you think? It's false.

Do we know why? Well, if you think about it, you can't have yes or no for lunch.

The question was, "What are you having for lunch today?" Some people might have sandwiches, some people might have a hot dinner, which means there might be different options on different days.

And if we answer a yes or a no, that's not gonna make sense so clearly from before, that's an example of an open-ended question.

because we are giving lots of different responses rather than just a simple yes or no.

Let's try another one.

Is it true or false that you can answer this question with a yes or a no answer? Is water wet? Well done.

It's true.

Water is definitely wet.

It's a statement, it's a fact.

It doesn't have to have any opinion related to it so we can give a yes or a no answer, and that means that the why it's true is because the answer can only be yes or no.

I want you to have a go at some of those now.

You are gonna decide which of the questions that I pose to you can be answered with a yes or a no answer and which questions we might consider are open-ended.

You're gonna have to think really carefully about each one and it helps to think what answer you personally would give to the questions.

So questions are, "When do you eat breakfast?" Be thinking whether you would answer yes or no firstly to that.

And if it's not a yes or no answer, think what your answer would be.

The next question will be, "How do you get to school each morning?" Followed by, "Is it raining?" Then the next question is, "What is your favourite food?" And the next question, "Is a parrot a bird?" Lastly, the question I want you to consider is are the walls in the classroom pink? Pause the video and have a go at those now.

We'll consider what each answer should be and then consider whether it's a yes-no answer or an open-ended question.

Well done.

You thought very carefully about that.

And let's check to see what the answers are.

So our first question was, "When do you eat breakfast?" Well, that's an open-ended question.

This morning, I ate breakfast at half seven so I know I'm giving a time.

You might have had yours a bit later, but we are not gonna answer yes or no to that question because we've got the start of the question as when.

When indicates a time so that makes it open-ended because there are so many different times that we can have breakfast.

The second question was, "How'd you get to school each morning?" Again, if we focus on the word how, we can see that that's an open-ended question.

We are looking for the way that you got to school.

Some people might have walked, some people might have used public transport, other people might have used their parents' car.

The third question was, "Is it raining?" Now that's a yes-no question.

It can only be raining or not raining.

There's not really any benefit from saying it's something in between.

If there's rain falling down, we would say, "Yes, it is raining." If there's no rain in the sky, then we'd say, "No." There's no way we can elaborate further on that or any need to elaborate more.

The next question was, "What is your favourite food?" Again, that's an open-ended question.

We're starting to see a pattern here.

We've got the word at the front of the question what.

So that indicates to me that you're having to explain what your favourite food is and giving examples.

There are lots of different choices and everyone will have lots of different opinions.

So that makes it an open-ended question.

The next question was, "Is a parrot a bird?" That's an example of a yes-no question.

We've got a statement and then we checking is a parrot bird, and it's either a yes or a no response.

Like the previous yes-no question "Is it raining?" We've got the word at the start of the question is.

It's more of a statement that we've made into a question which can only give two answers.

Finally, the last question was, "Are the walls in the classroom pink?" That's an example, again, of a yes-no question, but this one's different in that we haven't used the key word is at the start of the question.

We've used the word are, but again, we could read that as a statement and that would give us either a yes or a no answer.

It can seem quite tricky sometimes, but always helps to think about what answer you would give to that question and it soon becomes obvious which ones you can answer yes or no to, and which ones you need to explain in a bit more detail.

Let's get onto the second part of our lesson today where we're going to use yes-no questions to split a group of objects.

Let's consider the question, "What is an object?" Now that's an example of an open-ended question.

We can't just answer yes or no.

We've got to think of detail.

Objects are important to us because we need to be able to ask questions about objects.

So we'd say that an object is something that is uniquely identifiable and has attributes.

It means that we can spot what it is, give a name to it, and be able to describe it.

Those things called attributes are words or phrases that can be used to describe our object such as its colour, its size, or its price.

We've said before as well that an attribute can sometimes be known as a property.

The house is big, the car is fast, and so on and so forth.

If we consider an example of an object, in a classroom, we might see a ruler.

The object has a name ruler, but also the object is going to have attributes, and those attributes would describe the features of that particular object.

We might consider the colour of the ruler.

In this case, it's brown.

We might think, "What is the ruler made of?" In this case, in my example, it's made of wood.

We can have objects that are named in the same way but might have different attributes.

So rulers aren't always brown and wooden.

Some rulers are clear and plastic.

These attributes letters understand the differences between different objects.

Let's try and put that into a sentence.

So I want you to use those two key words from today, object and attributes.

And I want you to think where in that sentence they are best placed.

Well done.

An object is something that is uniquely identifiable and has attributes.

We give objects names and we describe what they appear as and what makes them up by using attributes.

Let's try and do that with a few more examples now.

I'm gonna get you to use the following questions and answers to guess which object I have chosen.

So I want you to give me the name of the object based on the attributes in the questions from the answers that you would give.

So the first question I'm going to use is a yes-no question.

Is it red? The object that I'm thinking of is red so my answer is yes.

Look at the objects and think which of those objects applies to that particular attribute.

Which of those objects is red? Next I might be asked, "Does it have any plastic?" Again, the object that I'm looking at does have plastic.

It might make sense then to think about does it write? Some of those objects we look at are able to write words when we use them.

Others don't necessarily write those words, so it might help us eliminate some of the things that we thinking of.

So in my case, no, my object doesn't write.

Now can you think which object I chose based on all of those questions from before and the answers? Have a think.

The correct answer was the pair of scissors.

Scissors have the attribute of red.

They also have the attribute that they have plastic.

If you notice the handles are made of plastic.

And importantly, when I was asked the question, "Are you able to write with it?" I can't write with those pair of scissors.

So we eliminate the other red items, which was the pen and the pencil, the ones that we could write with, and we eliminate the book because the book doesn't have plastic on it.

That goes to show then that if we ask yes-no questions, we can actually use those yes-no questions to group objects.

Can you think what question might have been asked to group these particular objects together? The question was, "Does it have red on it?" The box on the left are all the objects that are coloured red.

And you'll notice it creates a second group where none of the objects are red.

So because we asked a yes-no question, we've created two possible groups, a yes group and a no group.

Yes, those objects are red.

No, those objects are not red.

So as Andeep's saying, "It's got some red on it so that's our yes group." And he's also spotting that those objects don't have red in them so that's our no group.

Let's try that again with another question.

Have a think.

What question has been asked to group these objects? The question asked was, "Can you write with it?" Now, it doesn't necessarily mean the group on the left is yes and the group on the right is no.

As long as we know which group is which and put the objects into the different categories based on that, we have grouped them all by the similar attributes.

So the writing pencil, the pen, and the colouring pencil have all been grouped together because we can write with them.

We can't write with the ruler, the rubber, the book, the sharpener, the scissors, or the glue.

And Andeep is checking that for us, no, these objects don't write, and yes, these objects write.

So because our question was a yes-no answer, that's created two groups and objects can either be in one or the other.

And because we've got so many attributes for these objects, we can think of lots of other ways to group the objects.

Have you got any ideas? Well remember, we've been grouping objects by their attributes.

Is it red? There are some objects that have some red on them.

We have some objects that don't have red on them.

If we put those objects in, all the red objects would go in the group of yes, there is some red colour on them, and the rest of the objects would go to the no red section.

Our attributes in this case is colour and our yes-no question lets us group them by that particular attribute.

We can pick whatever attribute we'd like.

Let's think about the question, "Does it have any wood?" Now, objects are either gonna have some wood on them or they're gonna have no wood whatsoever.

Our attribute in this case is the material, so what the object is made from.

Again, if we worked through each of the items we'd see, that the pencil, the writing pencil, the ruler, they are all objects where the material has some wood.

The remaining objects that don't have wood would be grouped in the other category.

And that category is that they have no wood.

Let's try a few more examples.

Do you learn about computing at your school? Is it raining? Is it morning? Does your school start at 9:00 AM? Now they're great examples of yes-no questions.

You probably only express them as a yes-no response.

So we'd say that each answer is either yes or no.

Look at the start of each of the questions as well.

We've got the words is, do, or does.

We're not asking for specific examples, we're not asking for opinions.

We're asking for facts that are either yes or no, true or false.

And let's try and think of good questions that we could ask about this motorbike.

And let's think of some sentence starters that we might use to frame our questions.

Good questions that we'd find out attributes of the motorbike could start, is it, does it, but remember the answer must only ever be yes or no.

Have a think about some of the questions that we could ask using those sentence starters.

Because the motorbike has so many different attributes, we'll have lots and lots of different questions.

I could have used a question such as, "Is it red?" In which case the motorbike is red so I would say, "Yes, it is red." I might ask, "Does it have two wheels?" In this case, the motorbike has two wheels so I'd say yes.

We could ask different questions about the same attribute so number of wheels in this case is two, but perhaps my question if I didn't know what I was looking for might be, "Does it have four wheels?" Because I might be looking for a car.

In which case the answer for the motorbike in question would be no, because it only has two wheels.

It helps when we look at lots of objects that we want to compare side by side.

And if we had to think about it, what questions could you ask to make two similar-sized groups using these objects? Now, we're not gonna get them exactly right because there's an odd number.

So we might have a group of three and a group of four.

In this particular grouping, Andeep has asked, "Does it have handlebars?" And we can see there that the group on the left all have handlebars and the group on the right don't.

We'd mark that so we know that we were looking at.

We would say that this group has handlebars, and we would say that this group does not have handlebars.

Andeep's asked a really good question because it's a yes-no question, and it splits the object into two similar-sized groups.

In this case, we've got three, and in the case of no handlebars, four.

Now this example is not a great example because we've got an uneven split.

Andeep asks, "Does it fly?" We've got the aeroplane which flies, and we've got all the other objects which do not fly.

Whilst that's a yes-no question, it hasn't split the objects into two similar-sized groups.

We've got a group of one and a group of six.

You are gonna have a go now at putting some of that into practise.

So for task B, I'm gonna get you to think about the questions that you could write to group the objects into similar-sized groups.

You can see my objects at the top of the table there, and I've got a column where you work out how many were yes answers and how many were no answers.

So in my example, I've asked the question, and it's a yes-no question importantly, "Does it have handlebars?" So I go across the row and I put a tick If my item has handlebars, which is why I've ticked the green bike first.

I've gone onto the campervan which doesn't have handlebars so I put a cross because it's a no answer.

And I carry that all the way along until I've got ticks and crosses.

I count the number of ticks that I've got, which is three, so the green bike, the blue bike, and the motorbike.

And I count all the crosses where there was a no response, which was the campervan, the bus, the car, and the aeroplane.

So that's a total of four nos.

I want you to use those same objects and think of other questions that you could ask which would create similar-sized groups.

Take your time and think carefully about that 'cause you want to keep track of how many are in each group trying to get a split of three to four or four to three.

Pause the video and have a go now and I'll show you some examples I come up with a little bit later.

Well done.

That was quite tricky.

And you probably changed some of your questions as you went along, but that's okay.

It takes a while to get used to, and we should be thinking about what leads to the best outcomes.

I could have asked a question, "Does it have windows?" And you'll notice that some of them do and some of them don't.

And it's a good question because it's a yes-no question.

So we can see the campervan, the bus, and the car are all objects that have windows, which means there's four objects that don't.

My second question was, "Does it have more than two wheels?" Definitely a yes or a no question 'cause its saying it has more than two wheels.

More than two wheels means three, four, five, six, and so on.

If I'd have asked that question differently and more in an open-ended way, I wouldn't have been able to do this.

If I'd have asked, "How many wheels does the object have?" I might have got different answers.

I've got another question about wheels.

Does it have four wheels? So this time I'm being more exact, but again, it does allow me to give a yes-no response.

As we can see there, there are three objects that do have exactly four wheels.

My last question, "Does it have more than two seats?" And we can see that the green bike, the blue bike, the motorbike, and the aeroplane only have single seats.

So that's why we've got a negative response and no response to that question.

But each time that each of those questions, I was able to split it in a group of three and a group of four, which is roughly equivalent.

You will have got lots of different questions, but hopefully, you will manage to split them equally.

Well done.

We covered a lot in that lesson today.

Let's just think back as to what we've seen.

We found out that some questions can only have yes or no answers.

Often we were refer to them as closed questions 'cause they can only have those two responses.

We can use questions to make up specific groups of objects.

By asking the right questions and getting closed responses, we are able to make groups of objects based on what we're looking for.

And when we want to get those groups of objects, it makes sense for us to ask yes-no questions.

Open-ended questions don't allow us to give specific groupings which makes it difficult to draw groups out when we've got so many different answers.

We also found out that an object is something that is uniquely identifiable and has attributes.

We can name objects and we can use the attributes to describe the features of those objects.