Sampling, Data Presentation And Interpretation Flashcards
What is the IV and DV
The total weight in a lift and the number of people in the lift
IV= number of people in the lift
DV= total weight in the lift
what is defined as an outlier in terms of SD?
± 2SD from mean
what is defined as an outlier in terms of quartiles?
+ 1.5 IQR above UQ
-1.5 IQR below LQ
given you have 10 values how many modes would you have to have for the data to be evenly spread?
close to 10 or 0
How do you calculate variance from SD?
SD^2
How is the area under a histogram linked to the frequecy?
Proportional
What is the difference between interpolation and extrapolation?
inter= estimating within data set extra = estimating outside data set
What are the different sampling techniques
Random Stratified Systematic Cluster Opportunity
Describe random sampling
Data chosen at random
Repeats ignored
Describe Systematic sampling
Choosing data at regular intervals
Describe cluster sampling
Data is grouped into clusters and you choose clusters
Describe Stratified sampling
Data is proportional (combinen with random to get best results) to population
Describe opportunity sampling
Data selected from population that are available and fit the criteria
Advantages of random sampling
Fair and unbiased
Advantages of Systematic sampling
Unlikely to be bias
Advantages of cluster sampling
Quick and efficient
Advantages of Stratified sampling
Best way to fairly reflect pop
Advantages of opportunity sampling
Can be done immediately
Disadvantages of random sampling
Can be time consuming
Impractical on large scale
Disadvantages of Systematic sampling
May not be random
Disadvantages of cluster sampling
May be bias
Disadvantages of Stratified sampling
Time consuming
Impractical on large scale
Disadvantages of opportunity sampling
May be bias
