math Flashcards
numerical
- numerical is quantitative (can be in the form of any number)
- numerical can be continous (have any range 10-20, 30-40)
- numerical can be discrete ( has specfic values 2, 4, 8).
categorical
- categorical is qualitiave
- categorial can be seperated into several groups
- ordinal & nominal
Ordinal data
- ordinal data is data that can be ranked
- disagree, agree, somewhat agree
- not likely, likely
nominal data
nominal is data that can not be ranked
* blue eyes, green eyes, brown eyes
* summer, fall, winter, spring
the x axis of this graph is determine in mintues (0, 5, 10, 15, 20)
numerical continous
* because it can be anywhere between 5 and 10
this x axis is number of chairs
* 0,1,2,3,4
numerical discrete
* cuz there cant be a half of chair
this x axis is
* unsatifsfactory, good, excelent
categorical ordinal
this x axis is diffrent citites
categorical nominal
population
refers to all the indviduals who belong to the group being studied
sample
is a subset of the population. the sample is the group of indivudala that particapte in the survey
variabilites in samples
shows how samples are diffrent from each other. thr more similiar samples are to each other, the lower the variability and the more acuratley the samples represent the population
name all 7 sampling techniques
- simple random sample
- systematic sample
- stratified sample
- cluster sample
- multi-stage sample
- voluntrary response sample curvey
- convenicne sample
simple random sample
- every memeber of the population has an equal chance of being selected and the selection of any particular individual does not affect the chances of any other indivdual being chosen
- example- assign each member of the population with a unique number and randomly selected which members will be surveyed
systematic sample
- go through the population sequentially and select members will be surveyed
- example- every 10th person in the population is sampled
straitfied sample
- when the ppopulation contains groups of memebers who share a common charchteristic such as age, this group is reffered to as a sratum. a straitfied sample has the same propartion of members from each stratum as the population does
- example- there are 70 females teachers and 30 male teachers. a startaified sample of 10 teacher would have the same proporations, 7 females and 3 male teachers
cluster samples
- when you randomly select groups/clusters of people to be surveyed and everyone in the group is survyed
- example- you servey starbucks customers in toronto, randomly sleect a few starbucks in the area and survey every customer there
multi-stage sample
- it uses several levels of random sampling (it divides the population into hirearchy)
- examples- a survey is to be conducted on all people living in ontario
- the resarcher would randomly sleect the citites to be the survyed and then randomly select the houses within the chosen subdivision
voluntary response survey
- the researcher simply invites any member of the population to partcipate in this survey. within the method the sample typically will not represent the population
- example- any surveys that are conducted over the radio
convience sample
- when a sample is selected simply because it is easily accesable
- example- i wanted to conduct a survey on all the gr. 12 students, than you would survey the class.
primary source data
data that has been collected directly by the reasearcher and has not been manipulated or summairzed
observation studies
researches looks at situations that are already occuring and try to make infrences
* example- the comparison of two groups of people, one with memebers who excersice and another who dont, to see is one group is healthier
expiremental studies
researchers control what is going on and make infreneces based on those controls
* example- two similair groups are randomly chosen and have mebers that perfom rigiorus workout once a day for 30 days whill other members contuine with their nromal lifestyle, researchers measue the fitness of both groups at the end of the month
the 4 bias
response bias, samplign bias, non-response bias, measurement bias
response bias
occurs when particpients in a survey dileberatly give false or misleading answers (to aviod embaressment)
* if i were to survey a class and ask “ how many of you cheated on last weeks test?” you may not answer this question truthfully, because you dint want me to know
sampling bias
when the sampling does not closely represent the population
* survey students at a highschool football game and ask them whether the school should spend their extra-curciular- fund on new instruments for the band or new equipment for the football team
non-response bias
when the opinions of those who respond to the survey are significantly diffrent than those who do not respond
* a mail in survey asked respondent about their drinking habits. only 3% of the survey were returned. such a small return rate would likely not yeild a represtitative sample. in fact those who respond often have very strong opinions about the subject matter and so the results are over or under control
measurment bias
when the data-collection method isnt being implemented properly; the datda will either be over estimates or underestimated
* example- you wany to collect data on how fast cars are travelling on hwy 403 so you ask a police officer to drice on the 403 and record the speeding of each car using a radar
- example- you conduct in a survey in your school asking students
a) mrs blue
b)mrs green
c) other
this is an example of a leading question because you are giving the students some possible answers and this many influence their reposonse. it would not be a leading question if you were to list all possible answers (math teachers)
primary source data
data that has been collected directly by the searcher and has not been manipulated or summarized
microdata
an indivdual set of data about a single respondent
secondary source data
data used by someone other than these who actually collected them
aggregate data
data that combined or summarized in such a way that the individual microdata can no longer be determined
