a strength and limitation of random sampling
no researcher bias, unrepresentative
what is randomisation
the use of chance to reduce the effects of bias from investigator effects
how to eliminate order effects from repeated measures
counterbalancing
describe a single blind experiment
the researchers are aware of which subjects are receiving the independent variable, but the participants of the study are not
what is standardisation
keeping everything the same for all participants so that the investigation is fair
what is stratified sampling
a sampling method in which researchers first divide a population into smaller subgroups, or strata, based on shared characteristics of the members and then randomly select among each stratum to form the final sample
what is systematic sampling
a sampling method where every nth individual is selected from a list or sequence to form a sample, ensuring even and regular intervals between chosen subjects
what does it mean if a conclusion has high temporal validity
they can be generalised over time
describe time sampling and give a specific example
the researcher records all behaviours for a set time frame, at a set point, e.g. they record each participant behaviour for 20 seconds every 15 minutes over a 2 hour observation
what is validity
the extent to which research accurately measures what it’s intended to measure
describe volunteer sampling and give a specific example
people sign up for the study on their own accord e.g. by replying to an advert in a newspaper
why might volunteer sampling be biased/unrepresentative
everyone who signs up has a participant variable in common
what is interval data
anything measured in public, standardized units such as height or speed
what is ordinal data
any data on a rating scale, a position, or results of a non-standardized test
what is nominal data
measures how many people fall into each category. you can’t identify an individual score
give 3 measures of central tendency
mean, median, mode
give 2 measures of dispersion
range, standard deviation
when should the mean be used as a measure of central tendency
when there are no anomalies
when should the median be used as a measure of central tendency
when the mean cannot be used due to anomalies
when should the mode be used as a measure of central tendency
when there is a clear modal value. always use when dealing with nominal data
3 things to include when drawing a graph
a title with the IV and DV in it, labelled axis, IV on X-axis and DV on Y-axis
when is a bar chart used
when the data is discreet, in separate categories
do the columns touch in a bar chart
no
when is a histogram used
when the data is on a continuous scale e.g. when the numbers are consecutive on the x-axis
do the columns on a histogram touch
yes
when would a scattergram be used
when the relationship between two variables is being assessed in a correlation study
when would a line graph be used
when change over time is being measured
define normal distribution
When data is plotted on a graph, a bell-shaped curve is given, and the mean, median, and mode are all the same
give 2 examples of features believed to be normally distributed within the UK
IQ, height
which average is the biggest in a negatively skewed distribution
mode
which average is the biggest in a positively skewed distribution
mean
which direction is a negatively skewed distribution skewed towards
left
what is content analysis
involves the study of various media, from which psychologists indirectly observe communications between people
what is qualitative data
detailed data in the form of words
what is coding
breaking down qualitative data using categories and counting the number of times a category occurs
what is thematic analysis
looking for broader ‘themes’ in qualitative data, which may be decided after a content analysis
how is a sign test carried out
work out the differences between the two conditions. then make note of whether these are positive or negative. make note of the number of the less frequently occurring sign (this is calculated value). N is the number of participants, excluding those who’s sign was =. then use table, as 0.05 significance, to decide on the critical value
what is a type 1 error
an optimistic error, where the level of significance is too lenient
what is a type 2 error
a pessimistic error, where the level of significance is too strict
what does a stat test of a correlation need to achieve
a test of the significance of a relationship
what does a stat test comparing 2 conditions need to achieve
a test of significance in difference
which stat test would you use for a correlation that created interval data
pearson moment
which stat test would you use for a matched pairs design with ordinal data
wilcoxon sign
which stat test would you use for an independent measures design with nominal data
chi squared
anagram for choosing a sign test
NOIRSWRMSWRICMUCCSP
3 ways to improve reliability
train observers, standardise procedures, operationalize
3 ways to improve validity
controlled environment, standardise procedures, single or double-blind design
what is the aim of the ‘nudge unit’
to change the behaviour of the population, in a way that helps the government and economy, one small bit at a time
two ways in which psychology helps the economy
treatment for mental disorders like depression allows people to spend less time off work, research into role of the father reassures high-earning mothers that they can continue to work so families may maximise their income
what are the different sections of a report
Abstract, Overview of the approach, structure of the data, structure of the model, results, discussion, references
what is the structure of a book reference
Surname and initial of author, (year published) title of book, place of publishing, publisher, page number
what is the structure of a journal article reference
Surname and initial of writer (year published) ‘Title of study of theory’ cited, surname and initial of author, (year published) title of book, place of publishing, publisher, page number
what is the structure of a website reference
source, (year) title, weblink, date accessed
what is peer-review
the process by which research reports are sent, before publishing, to other, hopefully unbiased, psychologists who are specialists in the field being investigated. These psychologists will hopefully point out any unjustified conclusions or flaws in the method
2 limitations of peer-review
long process, only significant findings are published which may lead to bias within the field
2 strengths of peer review
ensures ethical research, prevents invalid findings from being published
define science
a branch of knowledge conducted on objective principles involving the systematised observation of and experiment which phenomena
give 8 features of science
objectivity, empirical method, replicability, falsifiability, theory construction, hypothesis testing, paradigms, paradigm shifts
give an acronym for the levels of data
ION