A
LEVEL
PSYCHOLOGY
PAPER
2:
RESEARCH
METHODS
Type
1
error**
-
ANSWER
The
null
hypothesis
is
rejected
and
an
alternative
hypothesis
is
accepted
when
the
null
hypothesis
is
true.
Optimistic
error,
more
likely
if
significance
level
is
too
lenient.
Type
2
error**
-
ANSWER
When
the
null
hypothesis
is
accepted
but
the
alternative
hypothesis
is
true.
Pessimistic
error,
more
likely
when
the
significance
level
is
too
low.
Reliability
-
ANSWER
Assessing
reliability
-
ANSWER
Test
re-test
reliability:
Inter-observer:
Correlation:
In
test
re-test
and
inter-observer
reliability,
the
scores
are
correlated
and
the
correlation
coeffiencey
should
exceed
+0.80
for
reliability
Improving
reliability*
-
ANSWER
Questionairres-
rewrite
questions:
questionnaires
that
produce
low
test
re-test
reliability
sometimes
need
to
be
rewritten.
Researcher
may
replace
some
open
questions
with
closed
ec.
Interviews-
improved
training:
Best
way
to
ensure
reliability
is
to
use
the
same
interviewer
each
time,
if
this
is
not
possible
all
interviewers
must
be
trained
so
they
avoid
leading
questions.
Experiments-
Standardised
procedures:
Observations:
operationalisation
of
behavioural
categories-
if
behavioural
categories
are
measurable
then
they
are
less
open
to
interpretation.
categories
should
not
overlap
and
all
possible
behaviours
should
be
included,
if
this
is
not
the
case
then
the
research
may
end
up
with
inconsistent
findings.
Validity
-
ANSWER
Assessing
validity
-
ANSWER
Improving
validity
-
ANSWER
Choosing
a
statistical
test
-
ANSWER
college
meals
upset
stomaches
with
tomatoes,
crisps,
sweets
&
Pepsi
Probability
-
ANSWER