mathematical skills Flashcards
what are the types of data?
quantitative
qualitative
what is a quantitative data?
numerical data
what is a strength of quantitative data?
P easy to make statistical comparisons without the risk of biased interpretation
C increases validity as we can accurately measure what was intended
what is a weakness of quantitative data?
P numbers do not provide reasons for ‘why’ behaviours have happened
C reduces validity as we are not accurately measuring what was meant to be measured
what is qualitative data?
rich and detailed descriptions e.g with words or pictures
what is a strength of qualitative data?
P shows the true nature of human behaviour
C increases validity as we can accurately measure what was intended
what is a weakness of qualitative data?
P creates an opinion, which then must be interpreted
C reduced validity as we are not accurately measuring what was meant to be measured
what are they types of data collection?
primary
secondary
what is the difference between primary and secondary data collections?
primary - collected by researcher to use in the current study
secondary - data was collected for another purpose in another study
what is a strength of primary data collection?
data collection is designed to fit the aims of the study
what are some weakness’ of primary data collection?
- lengthy
- expensive
e.g recruiting people, plans, carrying out etc.
what are some strengths of secondary data collection?
- simpler
- quicker
- cheaper
what is a weakness of secondary data collection?
may not fit the exact study and it’s needs
what are the levels of data?
nominal
ordinal
interval
what is nominal levelled data?
data in separate categories
e.g pets people own…pig, cow and crabs
what are strengths of nominal levelled data?
- easy to generate an answer
- large amounts of data collected
what are weakness’ of nominal levelled data?
- can only use the mode
- without a linear scale
what is ‘ord’ inal levelled data?
data that has some ‘ord’ er to it
e.g order of people running a race…gold, silver and bronze
what are the strengths of ordinal levelled data?
- more information than nominal data
- indicates a linear scale
what is a weakness of ordinal levelled data?
the gaps between values are not equal = no mean
what is interval levelled data?
data that is measured using units of equal intervals
e.g time…10 minutes is twice as long as 5 minutes
what are some strengths of interval levelled data?
- scientific
- reliable
- more information
- data is comparable
what are some weakness’ of interval levelled data?
- participants can demonstrate a variable
- no baseline if scientific methods are not used
what are examples of descriptive statistics?
range
variance
standard deviation
how to find the variance?
- find the mean of a data set
- each number is subtracted from the mean
- each number is then squared
- find the total of the squares
- have the squares divided by how many numbers are in the data set (-1)
how to find the standard deviation?
square root the variance
what is a strength of the variance?
produces a precise measure of spread as all data is used
what is a weakness of the variance?
may hide some of the characteristics of the data
e.g extreme values
what are some strengths of standard deviation?
- a precise measure of spread as all data is used
- produces smaller and more usable numbers than the variance
what are some weakness’ of standard deviation?
- harder to calculate than the range
- may hide characteristics such as extreme values
the order in to do a bar chart?
- make a title
- make a y-axis label
- make an x-axis label
- plot the data correctly
what data do we use on a histogram?
continuous data, ordinal data
what do line graphs show?
the change over time
if you were to record 8/20 on a pie chart, what percentage would it be? what degrees would it be?
40%
144°
what axis is frequency normally on?
y-axis
what shape does normal distribution give?
a symmetrical bell-shape
where is the mean, median and mode found on a normal distribution graph?
the mean, median, mode are all at the same point, at the mid-point of the curve
give an example of a variable that is shown on a normal distribution graph
height of people in a population
what does a normal distribution card show?
the vast majority of the data is around the centre of the graph/curve, very few data points at either end
draw a negatively skewed graph
draw a positively skewed graph
starting from the top of the curve, to down the slope, what order is the mean, median and mode?
the mode
the median
the mean
what is left-skewed data?
negatively skewed
what is right - skewed data?
positively skewed
if an exam was too hard, would it be positively or negatively skewed?
positive
