research methods part 3 Flashcards
what are the 3 measures of central tendency ?
mean
median
mode
what does central tendency represent ?
averages
- gives information about the most typical values in a set of data
what is an advantage of using the mean ?
most sensitive of all measures
takes all scores into account
what is a disadvantages of using the mean ?
can be easily distorted by extreme values
what are the advantages of using the median ?
extreme scores don’t affect it
really easy to calculate
what is the disadvantages of using the median ?
less sensitive then the median
as doesn’t include all scores
what is the advantages of using the mode ?
really easy to calculate
what is the disadvantages of using the mode ?
it is a crude measure
- avoid using it
- can be the only measure used if categories involved
what is measures of dispersion ?
based on measure of spread
tell us how far scores are spread from each other
what are the 2 types of measures of dispersion ?
range
standard deviation
what does a larger range and standard deviation mean ?
the bigger the the score then wider the spread
what is an advantage of using the range ?
really easy to calculate
what is the disadvantage of using the range ?
it only takes in the 2 extreme values
so may be unrepresentative of the data as a whole
what is an advantage of using standard deviation ?
more sophisticated than the range
as a more precise measure of dispersion
what is a disadvantage of using standard deviation ?
can be distorted by an extreme value
what is low standard deviation ?
all the data is tightly clustered round the mean
what is high standard deviation ?
scores are widely spread
and not all the pps were affected in the same way
what are the 4 types of graphs ?
bar charts
histograms
line graphs
scattergraphs
what is a bar chart ?
used for plotting discrete data
the types of data don’t overlap in anyway
what is discrete data ?
discontinuous data
-it doesn’t continue after been measured
- gaps between the bars
what is a histogram ?
similar to a bar chart
but it uses continuous data so not discrete
- no gaps between the bars
what is a line graph ?
usually used to show change over time or trials
what is a scatter graph ?
shows the relationship between 2 variables
how does normal distribution occur ?
as if u measure certain variables the frequency of the measurements should form a bell shaped curve
what does a normal distribution curve show ?
shows score that are symmetrical with the mean, median and mode at the highest peak
what are the 3 key features of a normal distribution ?
- all measures of central tendency at same point
- symmetrical from the midpoint
- dispersions of scores on either side of the midpoint is consistent and expressed as standard deviations
when does a skewed distribution curve occur ?
when data isn’t symmetrical
the data clusters towards one end
what is a left skewed distribution ?
it is negative
its tail is to the left so most data is towards the right
the mean is the lowest
and mode is the highest
what is a right skewed distribution ?
it is positive
it has a tail to the right so means most data is towards the left
mean is the highest
mode is the lowest
what happens to the median on a skewed distribution ?
always in the middle
what happens to the mode on a skewed distribution ?
always at the peak of the distribution
what happens to the mean on a skewed distribution ?
affected by extreme scores so gets dragged away from the centre
what are the 2 types of ratios ?
part to whole
part to part
what is a part to whole ratio used for ?
1 st number is the condition being studied
2nd number is the total amount of pps
c1; total no.
what is the part to part ratio used for ?
to show results for both conditions
c1:c2
what is probability important for ?
statistical testing
what is a significance level ?
the point at which the researcher can be confident that they have found a significant difference or correlation in the data
- so accept hypothesis and reject null hypothesis
- all studies have one
what is the standard level of significance accepted in psychology ?
0.05
5%
p< or equal too 0.05
what does p<or equal too 0.05 mean ?
the probability that the results were due to a fluke that the results could be due to a chance of it being a fluke
what is medicine significant level ?
0.01
1%
p<or equal too 0.01
can we prove a hypothesis is right for wrong ?
no
can only be content with finding out how likely it is to be true
how do you analysis data ?
analyse using descriptive data
do inferential testing/ statistics
what is descriptive statistics ?
all the measures of central tendency and dispersion
what does inferential testing/ statistics tell us ?
if are results are significant or not
- helps us make inferences about the data
what do statistical tests provide ?
a way to determine which hypothesis we accept or reject
- tell us the differences or relationships between variables due to chance or if they are statistically significant
when do we accept the research hypothesis ?
if statistically significant
what is an example of statistical tests ?
the sign test
what are the 3 conditions and reasons why u use the sign test ?
- looking for a difference
- experiment used repeated measure design
- data is nominal
what is nominal data ?
it can be organized into categories
what is the criteria for stats tests ?
- difference or correlation
- design- RM, MP (related), IG (unrelated data)
-level of measurement eg) nominal, ordinal, ratio, internal
what are the 2 components that the sign test gives ?
calculated value (s)
that we compare w the
critical value
for the results in a sign test to be significant what must happen ?
s value is less than or equal to the critical value
how do u calculate the sign test ?
- look at difference in columns
- note down the positives or negative numbers
- count up how many + and -
- lowest number is the S value out of the 2
- then compare with the critical value
how do you find the N value ?
- the total number of pps
but take away whichever ones were equal in both conditions
how do you calculate the critical value ?
to use the table you need the
- significant level
- number of pps
- which type of hypothesis ( 1 tail or 1 tail )
which hypothesis is 1 tailed ?
directional
which hypothesis is 2 tailed ?
non-directional
what are the 3 major functions of peer review ?
-allocate research funding
-validate the quality and relevance of research
-suggests amendments and improvements
what is allocating funding involved in peer review ?
- peer review takes place before any research to decide if it is worth investigating
- like medical research council can be involved in help
why is validating the quality and relevance of research involved in peer review ?
- as reviewers examine all aspects of the submitted report
eg) methods - to check accuracy and quality
why is suggesting amendments and improvements involved in peer review ?
- sometimes report is good but needs minor revisions
- like could be deemed inappropriate so should be withdrawn or retracted
what are the 2 issues and problems with peer review ?
- ‘file drawer’ problem
-bias
what is the ‘file drawer’ problem ?
- bias towards publishing studies with positive results
- negatives either are rejected or never submitted to public
- like for every 1 positive findings could be hundreds of negative placed away in filling cabinets
- so understanding of subject becomes distorted
what are the 3 types of bias in peer review ?
-objectivity
- institution bias
- gender
what is objectivity bias in peer review ?
- reviewer may strongly support an opposing view
- as many believe difficult to separate reviewer from personal, political and cultural views
- even if meant to be anonymous but not many researchers
what is institution bias in peer review ?
research from prestigious uni is favoured
what is gender bias in peer review ?
male researchers tend to favoured
what do we need to consider about what we may learn when doing psychological research in terms of the economy ?
- how it affect the economy
-benefits it
-devalues the prospects
what is an example for memory for the economy ?
save money on police resources as improved EWT
what is an example for social influence on the economy ?
minorities encourages to make changes to save money
what is an example for psychopathology for the economy ?
person can be treated quicker so saves money on further treatment
so they can return to work which contributes to the economy
what is an example of attachment for the economy ?
mothers stay at home so not contributing to taxes
secure attachment children become productive members of society and so they can hold down job that contribute to the economy
what is an example for approaches for the economy ?
spend money on technology to understand our cognitive process more
