Paper 2 - Advanced Info Flashcards
3 advantages of primary data
- collection method is known
- accuracy is known
- you can find answers to very specific questions
2 disadvantages of primary data
- time-consuming to collect
- expensive to collect
4 advantages of secondary data
- easy to obtain
- quick to obtain
- cheap to obtain
- data from some organisations can be more reliable than data you collect yourself
5 disadvantages of secondary data
- method of collection is unknown
- data might be out of date
- data may contain mistakes
- data may come from an unreliable source
- may be difficult to find answers to specific questions
Define simulation
Modelling random real life events to help you predict what could actually happen
Advantage of simulation
It may be easier and cheaper than collecting and analysing real data
What can you use a control group for?
Testing the effectiveness of a treatment
How to carry out an experiment with a control group
Use random selection to select two groups of people. Give the test group the treatment, and give the control group no treatment. Compare the results for the two groups to see how effective the treatment is.
What is a control group?
A group of people selected randomly from the population who are not subject to any factors under the investigation
Define extraneous variables
Any variables that you aren’t interested in but could affect the result of your experiment. You need to try to control these variables during an investigation.
What is a comparative pie chart?
A pie chart where the areas of the pie charts are in the same ratio as the two frequencies
Why use comparative pie charts over pie charts?
Drawing two pie charts the same size to represent them when they have different total frequencies would be misleading
What is the independent variable also known as?
The explanatory variable
What is the dependent variable also known as?
The response variable
When is a scatter diagram an appropriate diagram to use?
When the data is bivariate
What is linear correlation
When the points lie on / near a straight line
How can you draw outliers on a box plot?
Mark them with a X
What type of data do histograms represent?
Continuous, therefore there are no gaps between the bars
4 advantages of the mode
- easy to find
- is always a data value
- can be used with any type of data
- unaffected by open-ended or extreme values
2 disadvantages of the mode
- there may be no mode or sometimes more than one
- it cannot be used to calculate a measure of spread
4 advantages of the median
- easy to calculate
- unaffected by extreme values
- best to use when data is skewed
- can be used to help calculate quartiles, IQR and skew