When was the last time you ran an experiment?
Seriously -- I'd like you to think about it for a minute.
Pause the video and maybe even write down a few notes.
OK we're back.
Running experiments is really important, we do it all the time.
Whether we are making food, trying to find the fastest bus, or the shortest distance on a map.
We also run experiments on our family and friends; we learn very quickly
as children what makes our parents happy or upset.
We run experiments on our partners, our spouses, and maybe even with our colleagues
at work.In fact, the only way to learn anything about a system is
to disturb it and then observe it.
I tell my students : "if you stop experimenting, you've given up on life!"
and I really believe that.
I'm Kevin Dunn, from McMaster University in Hamilton, Canada.
I work in the Chemical Engineering department, but this course is not going
to be about Chemical Engineering.
My goal is to make the next 5 modules you are about to learn,
the most interesting course you will be able to take online.
This one is going to be memorable and useful.
I am going to teach you skills that you can use anywhere in your life -
and you don't need a University degree to learn them.
This course is about running experiments efficiently.What do I mean by that?
Efficiency is doing the least amount of work and getting the most amount of information.
For those of you that work in companies,
you know that you almost never get a chance to do experiments at work.
So when you get that chance, you have to make sure that you get it right the first time.
Now lets take a look at some examples.
The small things in life matter.
Let's take a look at boiling water; something we have all done before.
The aim with this experiment is to find the setting that uses the lowest total energy.
And because energy equals dollars, we want to reduce energy consumed as far as possible.
For our experiment, we have two pots: a glass pot and a metal pot.
We have electrical heat which we can adjust to a low, or high setting.
We can use the lid or leave the pot open.
So we have several combinations now, and I'm sure you can guess
which combination will use the lowest amount of energy.
We kind of have that intuitive understanding from having boiled water before.
Here's a quiz however that shows the different combinations.
Take a look at the options for a minute,
and pick the setting you think will have the lowest total energy.
We are going to come back to this example in a future class
and take a look at some actual numbers.
But if you have the tools, how about trying that experiment yourself before the next time?
Something many of us have also tried before is growing plants.
There are many things you can change.
For example: how much water do you feed the plant each day?
what is the best time to give the plant water: morning or evening?
which type of plant pot should you use (ones with holes or no holes at the bottom)?
what happens if you put a plastic cover
over the plant (to simulate a greenhouse) or leave it open?
what is the effect of fertilizer or no fertilizer?
Now there are too many combinations
and we are not sure what the best one will be unless we do the experiments to test them.
Another example is a car's gas mileage; some people call it fuel efficiency.
The gas mileage is a number that tells you how far you can drive your car on one liter
of gas (or petrol, as some of you might call it).
To improve fuel efficiency you might consider the following:
should you drive with the windows open or closed?
does the air-conditioner have a really strong effect on the gas mileage?
what about tire pressure: by how much does it affect fuel efficiency
if the tires are not fully pumped up?
can we spend more money and buy petrol that has a high octane rating;
is that going to be worth the extra cost?
and you might also consider how gas mileage decrease if there are people in the car.
Once again, we may have a good idea of how each one of these factors affects the gas milage,
but what about the combinations of them?
For example: you can have fully pumped tires,
but what happens if you load the car with many people then?
Google, and other web-based companies are trying experiments on us all the time.
Go to this page for an example, and take a look at Google's experiment on YouTube in 2009.
In this experiment they were considering the layout and colour of the page.
There were 1024 combinations that they tested.
And the most successful setting increased the number of user sign-ups by nearly 16%.
The best combination could not have easily been guessed,
or found efficiently by trial and error.
One of the students I teach in my class at McMaster recently tried optimizing the strength
of a concrete cladding that can be used on buildings.
He tested several factors: the ratio of of water:cement; adding plant or cellulose fibres
to the concrete; if adding steel mesh to see
if that improved the strength; and a few other factors.
These initial experiments helped him eliminate factors
that were not influencing the concrete's strength,
and then left him with only a few factors that really mattered.
He confirmed his predictions that adding plant material reduced the concrete strength,
but after his experiments he had a quantitative idea
of how just much it reduced concrete strength, not just a guess.
Companies are experimenting with all sorts of ways to improving their concrete.
Here's an interesting example of a company that's now adding recycled construction waste
and old building materials into their new concrete.
One common theme in all these examples is that they have two features: there is an objective
to improve something, and there are two or more factors we can change to make that improvement.
So there's an outcome we want to improve, and there are factors.
We'll learn more about these terms in the next video.
So I have just given you several examples to consider.
What I'd like you to do now, is to take some time, and think of your own experiment
that you can work on during the time that you take this course.
Write out the topic, and consider how you can use that to improve your life.
Consider a topic that can improve your community;
or a topic that you can even use at work.
Even better, I'd like you to perhaps make a short video about it,
upload the video to YouTube, and share the link on the forums, over here.
Describe your idea with all of us in this course.
I'm going to remind you about that again.
But for now, please get started with the next video.