Transcript PS: Introduction to Psycholinguistics

PS: Introduction to Psycholinguistics
Winter Term 2005/06
Instructor: Daniel Wiechmann
Office hours: Mon 2-3 pm
Email: [email protected]
Phone: 03641-944534
Web: www.daniel-wiechmann.net
Evaluating the results:
Just a theory?
Def. ‘theory’:
 A set of statements or principles devised
to explain a group of facts or phenomena,
especially one that has been repeatedly
tested or is widely accepted and can be
used to make predictions about natural
phenomena.
Evaluating the results:
The scientific hypothesis
Def: ‘hypothesis’
 A tentative explanation for an observation,
phenomenon, or scientific problem that
can be tested by further investigation.

 Universal
quantification (All X are Y)
 (implicit) formal structure of conditional
 (potentially) falsifiable
Evaluating the results:
types of variables
 Def: ‘variable’
 A symbol that can assume a set of values


(for sets > 1)
Compare: ‘constants’ have a fixed value
Evaluating the results:
types of variables: AC
 Independent variable


Occurs in antecedent of conditional (‚If‘-part)
Used to decribe object of investigation
 Dependent variable


Occurs in consequence of conditional (‚then‘part)
Its distribution/variation is to be explained by
independent variable‘s
Evaluating the results:
types of variables
 We need to formulate two hypothesis


Our claim under investigation:
alternative hypothesis (H1)
The hypothesis we will accept in the absence of
evidence for our hypothesis:
null hypothesis (H0)
(H0 is always logically complementary to H1)
Evaluating the results:
Example: Particle placement


Peter picked up NP[the book].
Peter picked NP[the book] up.
Question: When do speakers use which
construction?
Evaluating the results:
Example: Particle placement
H1: The placement of the particle is
contingent on the ‘heaviness’/length of
respective NP
H0: The placement of the particle is NOT
contingent on the ‘heaviness’/length of
respective NP
Evaluating the results:
Example
 Transform H1 (and H0) into
conditionals


If the respective postverbal NP is heavy,
then the particle will precede it.
The heavier the postverbal NP, the more
likely it is that the particle precedes it.
Important concepts
 Probability of error (p)
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
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Empirical science is all about finding evidence
against H0 (‘principle of falsification’; cf.
Popper 1964)
We generalize from samples to populations
p expresses the likelihood that the observed result
occurs, if H0 holds true
if p < 0.05 (level of significance), H1 will be
assumed