Logic is built up of ideas called premises.
Even if they seem logical, it's important to pay attention to those premises
to make sure that they're not made of straw.
Straw-man arguments are off-topic, oversimplified, exaggerated, or subtly
twisted versions of your argument,
that others can easily knock over, while still appearing logical.
For example, perhaps you're discussing whether vaccinations can help reduce the number
of people who fall sick from a particular virus.
In response, another person puts forward a counter-argument claiming pharmaceutical
companies make large profits by selling vaccines. The focus of the argument is
being shifted from the benefits of vaccination to profiteering.
It's also easy to think everybody agrees with your starting premises.
But, misunderstandings or false premises can be slipped in.
For example, you can say that the measles make you sick,
the measles vaccine contains the measles virus and therefore the measles vaccine
makes you sick.
On these simplified facts this conclusion is logical.
But the premises might not be so solid.
You need to show that the measles vaccine which contains the same virus is
present in the form that makes you sick.
The measles vaccine actually contains a broken form of the virus that reproduces
slowly and doesn't make you sick.
This is a subtle, but rather significant difference.
Even oversimplifying a disagreement down to for and against, true or false,
black and white,
may be used to mislead you.
Remember, there can be more than one solution.