Hypothetical Reasoning &
Assumptions
© www.TeachCriticalThinking.com 2010
Assessing and Developing Argument
Hypothetical Reasoning and Assumptions
Textbook references are from the OCR AS book (Jo Lally)
Lesson Objectives
1) Review Argument structures
2) To understand how to identify hypothetical
claims and reasoning.
3) To be able to clarify any assumptions ‘made’
in a passage.
Homework Review/ Starter
Your homework was:
Write 5 simple arguments.
– 3 x simple with one reason
– 1 each with 2 & 3 reasons.
Homework review & lesson starter:
For your partner’s 5 arguments identify the
reason(s) and the conclusion.
Claims
• A claim is a statement or judgement that can be
challenged.
•
•
•
•
Claims can be:
Facts
Opinions
A statement of principle
• Reasons and conclusions are claims
Hypothetical Reasoning
• A Hypothetical claim is a statement in the
form:
• If this happens, then that will happen.’
• “If I stay up late, then I will be tired in the
morning.”
Hypothetical Reasoning
• A hypothetical claim can be used as a reason or a
conclusion.
• Hypothetical reasoning examines the consequences that
might arise if something were the case.
• Remember in the exam to include both the “If…” and
“then…” parts.
• Be careful – the examiners sometimes phrase the
passage so that the “then” word is missing!
Hypothetical Reasoning
Complete the following to make them into
hypothetical reasons:
1.
2.
3.
4.
If
If
If
If
you do not complete your homework …
she works hard at school …
he receives a text …
mum finds out …
Hypothetical reasoning
• Read & discuss Activity 8 page 23.
• Identify the hypothetical reasoning in each
of the three passages in Activity 9 page
24.
Activity
• List all of the argument elements we have
covered so far.
• Now write a simple argument which
includes all of these elements. Base your
argument around the school canteen.
5 mins to write
5 mins to share
3 mins to improve
Assumptions
• An Assumption is an Unstated Reason
without which the conclusion can not be
drawn.
– Learn this definition
• An Assumption is essential for the conclusion to
•
•
be drawn – the author accepts it to be true.
An Assumption is never included in the author’s
passage.
The conclusion will NOT work if the assumption
were not true.
Simple Assumptions
• It is raining outside therefore you should
not go out.
Identify some assumptions in the argument above.
Extension: Use the ‘Negative test’ or ‘Reverse test’ to see if
they are correct.
Hypothetical reasoning?
Simple Assumptions
• John has a history of criminal behaviour.
• A purse was stolen at the party.
• John was at the party.
• John stole the purse.
Identify some assumptions in the argument above.
Extension: Use the ‘Negative test’ or ‘Reverse test’ to see if
they are correct.
Simple Assumptions
• I voted Conservative.
• The Conservatives are in Power.
• I am therefore happy.
Identify some assumptions in the argument above.
Extension: Use the ‘Negative test’ or ‘Reverse test’ to see if
they are correct.
Simple Assumptions
• School canteen food is inexpensive
• It is of good quality
• They sell salads
• You should eat there
Identify some assumptions in the argument above.
Extension: Use the ‘Negative test’ or ‘Reverse test’ to see if
they are correct.
Simple Assumptions
• Freddie was marked present during
morning registration.
• He is not in my lesson period 1.
• Therefore Freddie is truanting.
Identify some assumptions in the argument above.
Extension: Use the ‘Negative test’ or ‘Reverse test’ to see if
they are correct.
Assumptions
• Read through pages 25 – 27. (5 mins)
• Discuss the pause for thought on page 28 with your partner.
• Identify an assumption made for the two arguments in activity 10.
• Rewrite the arguments in activity 10 in standard argument format
and include your assumption as a ‘new’ reason.
• Now read the passage at the bottom of page 28 (Oxford and
Cambridge graduates) and identify the conclusion. Repeat for the
passage on page 29 (Met office).
• Now do Activity 11 on page 30.
• Finally try the exam question – Activity 12 page 32.
Assumptions - Homework
• Formulating Assumptions and the
Reverse/ Negative Test.
• Read through pages 32 – 37 and answer
activities 13 & 14.
Assessing and Developing Argument
Hypothetical Reasoning and Assumptions
Reviewing the Lesson Objectives
1) Review Argument structures
2) To understand how to identify hypothetical
claims and reasoning.
3) To be able to clarify any assumptions ‘made’
in a passage.
Hypothetical Reasoning
& Assumptions
© www.TeachCriticalThinking.com 2010