wk 1 Flashcards
PREPARATION FOR EXAM
what is a sampling error and the equation
the difference between a characteristic’s value in the population parameter and its value in a sample statistic from that population.
Sampling Error = Parameter - Statistic
define parameter and statistic
parameter - a descriptive measure from
the population
statistic -a descriptive measure from
a sample
name and define the 2 types of qualitative data
provide examples
nominal,- used to categorise data( gender, hair colour )
ordinal- indicates rank or order (review scale)
name and define the 2 types of quantitative data
provide examples
discrete - data that we collect that can be counted and that only has a certain number of values (people in a class, test questions answered correctly)
continuous - Continuous data is data that can take any value. (Height, weight, temperature and length)
what is interval level data?
examples
Data are always numerical and distances between consecutive integers have meaning
Differences between numbers are equal
The location of zero is a matter of convenience or convention and not a natural or fixed data point
Example: Calendar time
how is ratio level data different to interval?
same properties as interval data, with the
additional property that zero has a meaning and represents the absence of the phenomenon being measured. The ratio of two values is also meaningful
what is random sampling and what are the 4 types
Subjects of the sample are chosen randomly from the population with a known probability.
Four types: SRS, systematic, stratified and cluster
define Simple Random Sample (SRS)
Every individual or item from the sampling frame* has an equal chance of being selected
*sampling frame = listing of population
define Systematic Sampling
a systematic sample is chosen from an ordered list of the population, with the starting point chosen randomly and each successive sample member selected systematically.
explain how to conduct systematic sampling
Define sampling frame = listing of population N
* Decide on sample size (n) and calculate k:
k = N/n
* Randomly select a starting point between 1 and k
* Select every kth individual after that
name the sampling method that involves dividing the population into two or more strata according to some common characteristic
stratified sampling
how do you conduct