Transcript Experiments 2: formulating & testing hypotheses

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What is a hypothesis?
Give an example of a hypothesis, based on a
study you know about.
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Today’s session
You will learn about
Context
& testing
Studies of social and
experimental hypotheses cognitive psychology
Summarising data using
mean & standard
deviation
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Formulating
Hypothesis
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A prediction about the outcome of a piece of
research
An experimental hypothesis must predict the
effect of the IV on the DV
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Experimental hypotheses
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A researcher dressed in uniform will be
obeyed more often than a researcher
dressed in civilian clothes.
Words that PPs have processed semantically
are more likely to be recognised than words
that they have processed structurally.
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Experimental hypotheses
Suggest experimental hypotheses for the
following studies:
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Jenkins & Dallenbach (1924)
Godden & Baddeley (1975)
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Experimental hypotheses
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Directional hypotheses predict the direction in
which the results are expected to run
Non-directional hypotheses predict an effect
of the IV on the DV, but not a direction
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PPs who learn the word list before sleeping
will recall more words than PPs who learn the
list after waking.
There will be a difference in the number of
words recalled between PPs who learn the
list before sleeping and those who learn it
after waking.
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Jenkins & Dallenbach (1924)
Testing hypotheses
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Hypotheses predict results of experiments
They must be tested against the data and
either accepted or rejected
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Summarising data
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Before we can assess whether the data
support or challenge the experimental
hypothesis we must prepare a statistical
summary
Any set of data can be summarised to two
figures:
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Central tendency
Dispersion
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Summarising data
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Central tendency
Tells you a typical value
from a set of data
Mode
Median
Mean
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Dispersion
Tells you how close to
the central tendency
the values in the set
are
Range
Standard deviation
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Concept maps vs. notes
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IV: revision strategy used
DV: score on a recall test (max. 20)
H1: PPs using concept maps will recall more than PPs using
notes.
Concept map
Notes
Mean
15.6
13.7
S.Deviation
5.2
2.3
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Organised vs. disorganised
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IV: info in categories or randomised
DV: score on a recall test (max. 20)
H1: there will be a difference in recall between PPs who are
give organised info and PPs who are given disorganised info.
Organised
Disorganised
Mean
13.4
12.3
S.Deviation
1.6
6.2
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Review
Identify…
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One thing you already knew
One fact you learned
One skill you developed
Something that was difficult and will need more
work.
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