Types of data Flashcards
sampling methods
ensure that info you collect will enable you to answer you research question
inference
provides the means to draw conclusions about a group of cases based on a selection from the group
quantitative data
involves numerical values made up of discrete or continuous data
qualitative
does not include numerical values includes categorical data
ordinal data
relationship between the categories (they can be ordered)
Lickert scales
ordinal scales representing the degree of agreement with the statement
Nominal data
no numerical relationship between categories (only distinguishing factor is the name of the diet)
Which two types of data make up quantitative data?
discrete and continuous
Which three types of data make up qualitative data?
nominal, ordinal and binary
population
all the members of the particular group understudy
sample
example of the population
inference
take a sample and draw conclusions about the population based upon the results from the sample
what must a inference sample be?
large enough to detect any differences that are of interest
representative of the population
If the sample is too small?
fail to provide sufficient evidence to answer the research question
if the sample is too large?
wasteful of resources and at worst unethical
two most common ways of preventing bias?
random sampling
stratified random sampling
Random sample
each member of the population has an equally likely, non-zero chance of being included
randomised trials
patients are allocated randomly to treatments, eliminate the effects of known and unknown factors
stratified sample
categories in the population that must be represented
convenience sample
not chosen randomly but is all that is availible
how would you display categorical data
bar chart or pie chart
how would you display continuous data
histograms, stem and leaf plots and box and whisker plots are useful
what is a pie chart good at
representing proportions in each category
what is need for a frequency table
summarises the frequency distributions function
what is a histogram used for?
summarises continuous, grouped data
relative frequency
the ratio of the frequency in that class to the total frequency
advantage of a stem and leaf diagram over a histogram
easier to construct
the individual values of the data are shown
box and whisker plots
show info based on the variability of the data, expressed through quartiles
