Intro To Measurement Flashcards
What is a variable?
Variables have more then one state, as well as different values just like numbers.
What is type 1 data?
Also known as discrete data, this form of data takes on limited number values.
What is type 2 data?
Also know as continuous data, this data has the longest/highest value On a scale.
What does NOIR stand for and what is it?
Nominal- classification (boy/girl)
Ordinal- order (1st,2nd,3rd)
Interval- difference between data points
Ratio- difference between the data scores
These are all types of measurement
What do we use average and variation for?
To summarise and describe data, to infer real differences and associations to generalise to the wider population
What is variability ?
The ‘spread’ of the average
What is the mode?
The data point that occurs the most common, it has no associated measure of variability
What is the median ?
We use the median to calculate the middle of the data this allows us to calculate the IQR to identify the distribution of the data
What is the mean and what do we use it for?
The mean is used to calculate an average of the data presented we can use it to calculate the variance and standard deviation which allows us to see how the data deviates from the average score
How to calculate SD
- Add all numbers
- Divide by total number (=0)
- Then we square all the scores
- Divide sum of squares by total scores
What is standard deviation?
The measurement of the average deviation of scores from the mean in the original units of measurement
O2x=E(x-n)2 what is this equation used to work out?
Population variance
S2x=E(x-^x)2 what is this equation used to calculate ?
Sample variance
What measurement of data do you need for SD?
Interval or ratio data
What type of measurement is used to calculate the IQR?
Ordinal data
