Heads up! To view this whole video, sign in with your Courses account or enroll in your free 7-day trial. Sign In Enroll
Well done!
You have completed Designing Interactions!
You have completed Designing Interactions!
Preview
There are several laws in Interaction Design. These psychological principles help guide designers to make intuitive user interfaces. We'll look at three popular laws: Hick's, Fitts's, and Tesler's.
New Terms:
- Hick’s Law: The more choices a person is presented with, the longer the person will take to reach a decision.
- Tesler’s Law (aka Law of conservation of complexity): Every application has an inherent amount of complexity that cannot be removed or hidden.
- Fitts’s law: The amount of time required for a person to move a cursor to a target area is a function of the distance to the target divided by the size of the target. Thus, the longer the distance and the smaller the target’s size, the longer it takes. source: interaction-design.org
Further Reading:
Related Discussions
Have questions about this video? Start a discussion with the community and Treehouse staff.
Sign upRelated Discussions
Have questions about this video? Start a discussion with the community and Treehouse staff.
Sign up
The field of interaction design consists
of several psychological principles.
0:00
In this video,
we'll take a look at three laws,
0:05
Hick's Law, Fitts's Law and Tesler's Law.
0:09
Hick's Law states that the more
choices a person is presented with,
0:14
the longer the person will
take to reach a decision.
0:18
It was defined by psychologist
William Edmund Hick.
0:22
Applied to design,
0:25
this means user interfaces should
be created with simplicity in mind.
0:27
Make content interactive and
provide categories, sorting, filtering and
0:32
sections to allow the user to narrow
down what they'd like to see.
0:38
This reduces cognitive load and
makes it easier to use the products.
0:43
Next up is Tesler's Law.
0:48
It was articulated by Larry Tesler,
0:51
a computer scientist who works in
the field of human computer interaction.
0:53
It states that for
0:58
any system there's a certain amount
of complexity that cannot be reduced.
0:59
While Hick's law states user interfaces
should be simplified, Tesler's law
1:04
knows that there's a certain point where a
product cannot be simplified any further.
1:09
Let's imagine an ecommerce shop.
1:15
You can simply visit the website and
add products to your card, that's easy.
1:18
There's no need to enter any billing or
shipping information yet.
1:23
But when you're ready to check out,
1:28
the store will need payment and they'll
need to know where to ship the order.
1:30
Okay, so that's where
the inherent complexities lie.
1:35
But even so, several decisions can be
shifted to a back-end process, and
1:38
it's up to you as a UX designer
to identify these opportunities.
1:43
Perhaps as the user enters their address
the system offers recommendations
1:48
to auto-complete the street name,
city, state and zip code.
1:52
Even better, this serves a dual purpose
of ensuring the address is validated.
1:58
There can also be an option
to create an account,
2:03
which would save the previously
entered information for next time.
2:06
The last law we'll look at is Fitts' Law.
2:10
Coined by psychologist Paul Fitts,
it states the amount of time required for
2:14
a person to move a pointer
to a target area
2:19
is a function of the distance to the
target divided by the size of a target.
2:22
Now, that's a lot of
logic to make sense of.
2:28
To put it in simpler terms,
a target area that's small and far away
2:31
will take the user more time to interact
with than one that's larger and closer.
2:37
It sounds like common sense, but
2:42
it's laws like these that
help inform design decisions.
2:44
This is just a sampling of the laws
you will encounter in the field of
2:48
interaction design.
2:51
If you're hungry for more,
check out the teacher's notes.
2:53
May these principles guide and
inspire you in your next project.
2:57
In the next video,
we'll look at sensation and perception.
3:01
You need to sign up for Treehouse in order to download course files.
Sign upYou need to sign up for Treehouse in order to set up Workspace
Sign up