Predictive Analytics Applications
ratio : quantitative relation between 2 amounts →
interral : use when ratio is not meaningful → temperature
ordinal : use when there is meaningful ordering → teaching effectiveness We also discuss several other topics like What does carmagnole (kar-man-yole’) refer to?
nominative : no meaningful of ordering → gender
stratified random : divide population into non overlapping groups (strata), select random sample from strata
multistage cluster : divide population into sub - population (clusters) select clusters to sample
systematic sampling : list population, select random start point, sample each nth element
If you want to learn more check out Define systematics in biology.
Types of survey questions
Types of surveys
dichotomous : yes / no answers
multiple choices :
open - ended questions
variable : any characteristic of an element
quantitative : numbers that represent quantities
qualitative : falls into categories e.g. eyes color
Cross - sectional data : data collected at the same or approximately the same point in time
Time series data : data collected over different time periods
Types of data sources
Don't forget about the age old question of Define psychological disorder.
data warehousing : process of centralized data management
big data : massive amounts of data
population : all elements from a set of data
sample : subset of population
census : examination of all the population measurements
descriptive statistics : science of describing the important aspects of a set of measurements
statistical inference : science of using a sample of measurements to make generalizations If you want to learn more check out What is the lewis structure for carbon?
statistical model : set of assumptions about how samples are selected
probability sampling : sampling where we know the chance that each element in the population will be included in the sample
convenience sampling : convenient to sample
voluntary response sampling : participants self - select
judgement sampling : person extremely knowledgeable about population selects population that he / she feels are the most representable
target population : entire population of interest
sample frame : list from which we select sample
sampling error : difference between numerical descriptor and corresponding descriptor of sample
undercoverage : when some individuals are excluded when selecting sample
nonresponse : when some individuals were supposed to be included are not included
bias : when opinions of some who did survey vary a lot from these did not participate in survey
errors of observation : when recorder misobserves and marks wrong
recording error : when recorder incorrectly marks an answer
response bias : when respondents do not tell the truth
September 18, 2017
Chapter 2 Descriptive Statistics
If you want to learn more check out What are the benefits of globalized markets?
relative frequency → a proportion = frequency / total # of observations
percent frequency → relative frequency ✕ 100 %
We also discuss several other topics like What is the main evidence upon which the modern theory of evolution is based?
bars arranged in decreasing height from left to right