1.1.1 If HE is accepted
and later turns out
not to be true
1.1.2 More likely if a
lenient probability is
used e.g. 10% level.
1.2 Type II Error
1.2.1 If HE is rejected and it
later turns out to be true
1.2.2 More likely if a
strict probability is
used e.g. 1%
2 Parametric and
Non-Parametric Tests
2.1 Non-Parametric
2.1.1 Use nominal + ordinal data,
simple, often subjective
scales, tests for
significance, convert scores
to ranks
2.1.2 sign test,
Wilcoxon test,
Mann-Whitney,
chi-squared +
Spearman's
Rank Order
Correlation test
2.2 Parametric
2.2.1 Use interval/ratio data,
contains info. about size of
difference between scores,
more powerful test of
significance
2.2.2 Related t-test,
independent t-test,
Pearson's Product
Moment
Correlation test
3 Correlations
3.1 Test for a link/ association
between 2 key variables
3.1.1 Research Hypothesis (instead of HE) used
to predict relationship e.g. 'there will be a
significant correlation between variable A
and variable B'
3.2 Positive Correlation
3.2.1 Variable A
increases as
variable B increases
3.3 Negative
Correlation
3.3.1 Variable A increases
as variable B decreases
3.4 Zero Correlation
3.4.1 No pattern/ relationship
4 Directional Hypotheses
& Tails of Test
4.1 Non-directional
Hypotheses
4.1.1 There will be a
significant difference in
the DV when IV is
changed
4.1.2 Used by researchers to
reduce experimenter bias
(e.g. when rejecting
anomalies
4.1.3 2-tailed statistical
test
4.2 Directional Hypotheses
4.2.1 Predict a significant
increase or significant
decrease in DV when IV
is changed
4.2.2 Only used when there is
strong previous evidence
about the direction of the
results
4.2.3 1-tailed Statistical
test
5 Reliability
5.1 External Reliability (test
re-test)
5.1.1 How consistent a
method measures
over time when
repeated (same
people under same
conditions e.g. IQ test
5.1.2 Correlate the results of a test
conducted on one occaision with the
results of a test conducted on a later
occaision (with same subjects). High
positive correlation = reliable method
5.2 Inter rater/ Observer Reliability
5.2.1 content
analysis/
observational
studies
5.2.2 1.) Clearly describe behaviour
to record (categorise)
5.2.2.1 2.) Observe same
ppts. for same amount
of time, independently
5.2.2.1.1 3.) Compare
results, if 90%
similar = reliable,
consistent
method
6 Validity
6.1 To what extent have you
measured the factor you
set out to measure;
whether other factors have
affected your results
6.2 e.g. Bigelow set out to measure children's
understanding of friendship, but instead
may have measured their language ability
6.3 Methods of
establishing Validity::
6.3.1 1.) Face Validity: look
at the method to see if
it appears to measure
what it is supposed to
measure; open to bias
6.3.1.1 2.) Concurrent Validity: give same ppts. the new
test, and an established test which measures the
same thing (or questionnaire). Test scores for
correlation - significant positive = valid
6.3.1.1.1 3.) Ecological Validity:where
the conditions of a test are so
controlled that they do not
represent how a situation
would occur naturally
7 Sampling
7.1 Target Population =
people that your
hypothesis relates
to and from whom
the sample is taken
7.2 Generalise = predict
future behaviour of
TP on basis of the
result of sample
7.2.1 Q-Sort Cards: used to measure
self esteem, select 4 cards,
convert into score of mood
7.2.1.1 Reliability: test re-test = do test
again on same ppts. after two
weeks, same results = reliable
7.2.1.1.1 Validity: Compare result's
correlation with an established
study (questionnaire), significant
+ve correlation = valid
7.3 Random/ Systematic Sample:
everyone in TP has an equal chance
of being selected, assigned numbers
7.3.1 Opportunity Sample: people who
are willing and convenient, likely to
be unrepresentative
7.3.1.1 Stratified Sample: Divided into groups (e.g.
gender, nationality, age) then random
representative sample from each group
8 Ethical Guidelines
8.1 Informed Consent
8.1.1 Verbal or written consent
after information about task
is explained, no deception
8.2 Consent for studies
involving children
8.2.1 Consent from parents (if
under 16) and child
wherever possible
8.3 Right of Withdrawal
8.3.1 Informed of right to
leave study at any
time in brief,
informed of right to
withdraw information
in debrief
8.4 Deceiving Participant
8.4.1 Explained in debrief,
consent to be
deceived, knowing aim
may affect behaviour
8.5 Protection from Physical
and Psychological Harm
8.5.1 Must be aware of consequences of
investigation, should feel no worse about
themselves after investigation, normalise by
informing of other ppts., counselling
9 Hypotheses
9.1 Experimental (HE)
9.2 Null
(Ho)
9.3 Alternative (H1)
9.4 Research (HR)
10 Descriptive Statistics
10.1 Averages
10.1.1 summarise set of
data into 1 value
10.1.1.1 Compare 2 sets of scores
10.1.1.1.1 Central point of
2 sets of scores
10.1.2 Mean: interval/ratio data
10.1.3 Median: Ordinal data
10.1.4 Mode:
Nominal data
10.2 Measures of Dispersal
10.2.1 How spread out a set of scores are
10.2.2 Tells yous if your
ppts. scores are
consistent or variable
10.2.3 Range: largest - smallest value,
affected by extreme scores
10.2.4 Standard Deviation: uses all
scores, use for interval/ ratio
data, measures the deviation
of each score from the mean
11 Quantitative
& Qualitative
Methods
11.1 Quantitative
11.1.1 +Controls extraneous
variables, +Establish
C&E. +Can test
hypothesis, +Can carry
out statistical tests
11.2 Qualitative
11.2.1 +Generates new theories, +High face validity, +High ecological
validity, +High level of detail; understand behaviour better