Unit 3.2e Flashcards
What can give rise to qualitative, quantitative or ranked data?
Discrete or continuous variables
What is qualitative data?
Data that is descriptive and difficult to measure directly
How is qualitative data measured?
Using direct counts or by observation
What is quantitive data?
Data measured directly
How is quantitative data recorded?
It’s recorded as numbers
In comparison to quantitive data, how easy is it to analyse qualitative data?
It’s much more difficult to analyse
What is ranked data?
It’s data that is put into order of magnitude
What is the mean?
It’s the average value for the data set
What is the median?
It’s the middle value for the data set when data is ordered from lowest to highest
What is the mode?
It’s the most common value in the data set
Why are box plots used?
Box plots allow us to see variation within and between data sets
What is the lower quartile?
Median of the lower half of data
What is the upper quartile?
Median of upper half of data
What do error bars represent?
Variation of corresponding coordinates on a point
What can show standard deviation in a data set?
Error bars
What do error bars show about the data?
- how spread out the data is around the mean value
- reliability of the mean value
- likelihood of significant differences between data sets
When should you be wary of a data set?
When the error bar is really large
What is correlation?
The relationship between two variables where they both follow the same pattern
What is causation?
Something that exists if the changes in value of the independent variable are known to cause changes to the value of the dependent variable
What does correlation not equal?
Causation
