PL1010: Research Design and Methods Flashcards
Your Deck Mentor for the Research Design and Methods deck is Bogna. You can email bogna.frykowska@forward-college.eu with any questions/suggestions about the flashcards in this deck.
Categorical variable
Variable with scores that are not on a numeric scale
Descriptive statistics –
Summarise samples – giving someone the main points in a simple form To describe data, we will use graphical and numerical (statistical) techniques
Inferential statistics –
Examine patterns in the data and consider how much data we have You can then draw conclusions about a population based on the analysis of a sample. -> conceptual replication
Summarising
collecting and summarising data
Standardisation
creating a system in which data can be assigned values (high vs low vs average)
Statistical inference
the ability to draw general conclusions from samples
How many times does a particular score occur?
Percentages/Averages Scores for a particular variable (Frequency statement)
Do scores for one variable correlate with scores for the other variable?
Statement about association
How strong is the correlation or association between two variables?
Statement about association
Do I trust that there is a “genuine” association (relationship)?
Statement about relationship between two variables
Frequency Distribution?
show scores in order and their frequency of appearance in the sample
Negatively skewed
Positively Skewed
When not to describe the skew of data?
When we cannot put our scores in order , from lowest
to highest so when we are describing a categorical
variable with unordered categories
Unimodal?
One major peak
Bimodal
Two major peaks
Approximately symmetrical
The Sample Variance formula
the n-1 leads to an unbiased estimate
How do outliers and the mean relate to each other?
Outliers are extreme values that differ from most values in the data set. Because all values are used in the calculation of the mean, an outlier can have a dramatic effect on the mean by pulling the mean away from the majority of the values.
What happens to the mean, median and mode in a skewed distribution
in normal distributions, they all take on the same number
frequency distribution
pattern of frequencies of a variable
Why are histograms good?
effective visual summary of a variable’s central tendency and variability
Why is the IQR a good measure of variability?
Because it’s not affected by outliers like the range is as it only includes the middle 50% of data?
Difference between central tendency and variability?
Central Tendency just tells you where the most important point lie while variability sums up how far apart and thus generalisable they are.
standardised scores (z-scores)
Z-Score Formula
Falsifiability
capacity for some proposition, statement, theory or hypothesis to be proven wrong (through systematic empiricism) a basis provided by the null hypothesis
null hypothesis
states the contrary of the experimental or alternative hypothesis
falsifiable hypothesis
can be logically contradicted by an empirical test that can potentially be executed with existing technologies .
A linear correlation describes
Two variables that are either proportionate or anti proportionate
Correlation coefficient
A number also represented by “r” describes positive (r=1), negative (r=-1) or no correlation (0=r)
Face Validity
basic form of validity demonstrated when a measurement procedure superficially appears to measure what it claims to measure
Concurrent Validity
demonstrated when scores obtained from a new measure are directly related to scores obtained from an established measure of the same variable.
Predictive Validity
demonstrated when scores obtained from a measure accurately predict behaviour according to a theory.
Construct Validity
requires that the scores obtained from a measurement procedure behave exactly the same as the variable itself.
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.
Convergent Validity
demonstrated strong relationship between the scores obtained from two or more different methods
Divergent Validity
demonstrated by showing little or no relationship between the measurements and two constructs
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
Construct
hypothetical attributes or mechanisms that help explain and predict behaviour in a
theory
Operational Definition
procedure for indirectly measuring and defining a variable that cannot
be observed or measured directly. An operational definition specifies a measurement procedure (a set of operations) for measuring an external, observable behaviour and uses the resulting measurements as a
definition and a measurement of the hypothetical construct.
What is naturalistic observation
A form of non-participant observation where a researcher is in a natural setting in which behaviur usually occurs without interupting
What is In participant observation
researcher engages in the same activities as the people being observed
in order to observe and record their behaviour.
What are naturalistic observation usually used for
used to describe non-human behaviour or children
What are the benefits and disadvantages of naturalistic observation (5)
external validity: real world setting behaviour is not manipulated overcoming ethical barriers –> instigating spanking vs. observing spanking time-consuming: having to wait till behaviour occurs research is prone to interruptions
When is participant observation needed
When simple observation is not possible. e.g. studying cults or gangs because their presence would alter the behaviour
What are advantages and disadvantages of participant observations (5)
access to information and observation unavailable to mere outside observation high external validity because of naturalistic setting time consuming observation potentially dangerous for researcher (sensitive nature) observers presence might alter participants’ experience –> objectivity?
What is Structured observation?
or contrived observation is the observation of behaviour in settings arranged
specifically to facilitate the occurrence of specific behaviours so they don’t have to wait for them to happen
Advantages and Disadvantages of structured observations
can be held in laboratory or other controlled settings to percipitate the behaviour that they want to observe –> good for developmental psych can be held in what is perceived a sa natural environment (field setting) less time consuming how natural is the behaviour?
During a study using observational methods, it is common to have two observers record behaviour
simultaneously. What is the purpose for this procedure?
objectivity of the measurements
In an observational study of children diagnosed with autism spectrum disorder, you record how
much time each child spends playing alone during a 30-minute observation period. Which method
of quantifying behaviour is being used?
duration
When researchers use behavioural observation techniques to measure behaviours in movies, what
is the measurement process called?
content analysis
What are behavioural tasks
usually computer-controlled, structured tasks measured across multiple repeated trials that researchers use to collect behavioural measures such as
response times and task accuracy measures.
What are many behavioural tasks structured around?
human information processing like cognitive tasks assessing attention, memory, language and decision making
What can also be measured by behavioural tasks
attitudes, preferences aside from cognitions
What is the main measure of interest in behavioural tasks
not the usually correct answer but speed of the response (response or reaction time)
What is a task paradigm
task originally constructed to investigate a particular hypothesis is used and adapted to examine others subsequently providing a standard model for line of research
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
What do all of the components of the K-R20 mean
n / number of items SD p / the proportion of the participants whose response is coded 0 q / proportion of the participants whose response is coded 1
What are the components of cronbach’s alpha
the extension is that it includes the sum of the variance produces values between 0 and 1.00
What is Cohen’s Kappa formula, and what is it used for?
calculating inter-rater reliability not using a simplistic formula and relying on data prone to circumstances and chance
What do the elements of Cohen’s kappa mean
PA: observed per cent agreement PC; per cent agreement expected from chance
What do frequency distributions for a categorical variable not include?
cumulative percentages
Do these images show the same data?
Yes
What does a boxplot do?
summarises the data while showing the range, interquartile range, as well as the min, max and the median
How is the sample mean related to variance and standard deviation?
it is expanded on in the formulas for variance and standard deviation
Which graph describes a correct null hypothesis?
right
What are the five characteristics of normal distributions?
