Applied Chap 1 Flashcards
1 adv and 1 dis of a census
Should give completely accurate results
Cannot be used when test involved destruction
1 adv and 1 dis of a sample
Less time consuming
Sample may not be large enough to represent small sub-groups of population
1 adv and 1 dis of simple random
Each unit has an equal chance of being chosen
May not accurately reflect population
1 adv and 1 dis of systematic
Suitable for large samples and populations
Sample frame is needed
Stratified sampling
Divided into groups and a simple random sample is carried out in each group.
1 adv and 1 dis of stratified
Accurately reflects population
Sampling frame is needed
Quota sampling
Divided into groups based of characteristic. Reflects group proportion in population (same as stratified but not random). Once quota is full, ignore subsequent units that also meet the characteristic
1 adv and 1 dis of quota
No sampling frame required
Can depend on knowledge/expertise of researcher
1 adv and 1 dis of opportunity
Easy to carry out
Unlikely to provide representative sample
Quantitive
Numerical values. Discrete is you can count it. Continuous is you measure it
Qualitative
Non-numerical values like colour
LDS tips
‘tr’ trace means rainfall less than 0.05mm so use 0.025 in calculations
Wind speed measure in knots and Beaufort Scale
1Dm (decametre) is 10m
Pressure in hectopascals (hPa)= 100Pascals
Oktas is 1/8s of sky covered, 0-8, 9 values
Trace or n/a does not appear overseas.
N/a can be found in sunshine, windspeed, maximum gust
Discrete data
Count. Can only take specific values like shoe size or number of children
Basically just whole numbers
Continuous data
Measure. Can take any decimal value such as height or weight
