Stats T5 - T10 Flashcards
Correlation coefficient
A number also represented by “r” describes positive (r=1), negative (r=-1) or no correlation (0=r)
What needs to be taken into consideration for construct validity
based on many research studies that use the same measurement procedure and grows gradually as each new study contributes more evidence.
Test-retest reliability
established by comparing the scores obtained from two successive measurements of the same individuals and calculating a correlation between the two sets of scores.
Inter-rater reliability
degree of agreement between two observers who simultaneously record
measurements of the behaviours
Split-half reliability
obtained by splitting the items on a questionnaire or test in half, computing a
separate score for each half, and then calculating the degree of consistency between the two scores for a
group of participants.
What are the two types of measures of reliability
Successive and simultaneous measurements
What are a few physiological measures commonly used
monitoring
heart rate or blood pressure, measuring
galvanic skin response, imaging
techniques positron emission tomography
(PET) scanning magnetic resonance imaging
(MRI) electroencephalogram (EEG) magnetoencephalography (MEG).
What are two prerequisites of behavioural observations
behaviour is not disturbed observations are based in subjective judgments and intepretations which pose a threat to reliability so need for more than one observer
Archival research
involves looking at pre-existing records (archives) to measure behaviours or events
that occurred in the past
Content analysis
measuring the occurrence of specific events, actions or statements in written
text (e.g., literature, press reports, transcripts) or film/video recordings (e.g., movies, television programmes) or similar media
How is the issue of interpretation in observational designs addressed (3)
well-defined categories of behaviour well-trained observers multiple observers or coders to assess inter-rater reliability
What are behaviour categories
well/defined sets of behaviour that is to be observed which helps isolating relevant behaviours
How are observations quantified (3)
frequency: how many times does something occur in the given time-frame duration: for how long does a behaviour occur interval: does a behaviour occur in a given interval
When are the three quantification methods most appropriate
first two techniques are often well suited for specific behaviours but can lead to distorted
measurements in some situations. For example, a bird that sings continuously for the entire 30-minute
observation period would get a frequency score of only 1. Another bird that sings 25 times with
each song lasting two seconds would get a duration score of only 50 seconds. In such situations, the interval method provides a way to balance frequency and duration to obtain a more representative
measurement
How do observers overcome issues of complex situations that cannot be watched multiple times
creating a recorded sample or taking a general sample
How is a sample taken
first step in the
process of sampling observations is to divide the observation period into a series of time intervals.
What are the three forms of sampling
Time sampling: sequence of observe–record–observe–record is continued through the
series of intervals Event sampling: identifying one specific event or behaviour to be observed and recorded
during the first interval, then shifting attention to a different event or behaviour during the second
interval, and so on, for the full series of intervals. individual sampling: identifying one participant to be observed during the first interval,
then shifting attention to a different individual for the second interval, and so on
How is reliability and objectivity of observations made from content analysis archival research ensured?
behavioural categories and preparing a list of specific examples to define exactly
which events are included in each category being measured quantification methods for each behavioural category multiple observers and coders
What does reliability often refer to
the relationship between two measures as shown by its correlation
When is assessing split/half reliability common
single variable measured within a test containing multiple items so that the internal consistency can be evaluated
What is the issue of split-half reliability
scores obtained are only from half of the test items which is less reliable because it underestimates the true reliability of the full test
What is the Spearman-Brown formula, and what does it do?
adjusts the correlation between the halves of split-half reliability tests, the effect is to increase the size of the correlation to produce a better estimate for the full test
What problem of split-half reliability does the Kuder-Richardson Formula 20 solve
The idea that tests can be split in different ways which potentially skews the results
What is the Kuder-Richardson Formula 20
a formula to estimate the average of all possible split-half correlations obtainable but limited to tests with dichotomic answers
