Statistics, Census, GIS-Maps Flashcards
definition / population
the group you want to generalize to
entire set of persons with at least one common characteristic
sample selected from population
definition / sample
subset of population
too expensive and time consuming to collect data on entire population66
UD Decennial Census
attempts to count every person in short for m
what makes a survey valid statistically
must employ a method everyone has a measureable chance of being selected
definition / sampling error
error expected in probability sampling
composed of population parameter
sample size
standard error
difference than bias
what is typical margin of error
in simple cases, margin of error in a sample with 95% confidence equals
1/ sqrt(x) with x being number of respondents
i.e 1,000 samples - 0.0316
definition / sampling frame
listing of the accessible population from which you’ll draw your sample
example - phone book
non-probability sampling (two types)
non-probability sampling…convenience sampling - only those who are accessible
volunteer sampling - people volunteer to be sampled
ok for descriptive results, introduces bias
probability sampling (4 types)
simple random - each individual has equal chance of being selected
systematic - every xth individual is selected from list, starting at randomly chosen point
stratified - population may have two or more groups in study. provides best results because it ensures even coverage of population but maintains random selection probabilities
cluster - used when stratified or simple random sampling would be difficult and/or expensive
definition / mode
most frequent score in a distribution, can have more than 1, can be bi-modal
definition / mean
sum of scores divided by number of scores
definition / median
number occurring in middle
definition / range
difference between highest and lowest score
variance
measure of how spread out a distribution is
average squared deviation of each number
standard deviation
square root of variance
68% within 1 standard deviation
95% should be within 2 standard deviations
99% within 3 standard deviations
definition/dependent variable
the fact the researcher is interested in explaining (number of trips)
definition/independent variable
variable used to explain variation (GFA, number of units)
definition/ bias
difference between expected value of an estimator and real value of the parameter
sampling error vs bias
sampling error is natural consequence of sample size being smaller than population
bias is due to faulty design of survey. not a result of sample size so increasing sample size will not reduce bias in estimates
two categories of bias
measurement bias - due to errors in sampling
non representative sampling bias - also known as selection bias due to not random methods during selection. convenience sampling often happens here. can happen when non responses from certain groups is significant.
measurement bias (3 causes)
error occurring when recording data
intentionally asking leading questions, framing question in way to lead responses
inadvertent false responses by respondents (d0n’t understand q)
definition / snowball sample
picks up samples on the way. asking participants to suggest someone who might want to participate
census / 2000 census surveys (2)
short form - 100%
long form - 1 in 6 hh
census / 2010
short-form 100%
long form discontinued
acs used in place of long form
short form questions
number of persons in HH
household owned or rented
demographics of people in household
ACS
ongoing survey that provides data every year
measure changing and social and economic characteristics
only have a 1 year and 5 year estimates
1 year estimate is data for areas of 65,000. less reliable than 3 and 5, for analyzing large populations
5 year data for all areas, good for small populations, more reliable
Public Use Microdata Samples (PUMS)
computer files contain records for a sample of housing units with information on characteristics of each housing unit and the people in it
represent 1/1000, 1% and 5% samples of housing units
Metropolitan Statistical Area (MSA)
one city
50,000 or more population
or census defined urbanized area with 100,000_
Consolidated MSA
must meet MSA standard and have population of 1,000,000 or more
18 CMSAs in USA
Urbanized Area
densely settled area with population of 50,000 or more
geographic core of blocks with population density of 1,000 per sq. m
Blocks
smallest unit of 100% tabulation data. average size 100 ppl
Block Groups
smallest area for which sample data are available. usually 1,500 people, 300-3,000
census tracts
about 4,000 people
census trends (6)
south shifting population
browning of America
intermarriage increase
graying of America
gender shift
more grandparent headed households
population pyramid
based in 5 year increments
female on right, male on left
Gompertz growth curve
non-linear s curve
assumes growth begins slowly, increases momentum, reaches inflection point, then slows in increments
comparative method
based upon past trends in a different area (pattern area)
two cities have historically grown the same way
ratio method / shift share
assumes relationship between local area and larger area are constant
also called shift share
fastest growing state between 2000 and 2010
Nevada
one state that declined from 2000 to 2010
detroid
biggest numeric increase from 2000 to 2010
texas
fastest growing metro area 2000 to 2010
palm coast Florida
what was years of baby boomers
1946 to 1964
GIS Mapping Standard Colors for:
Industry
Low dens residential
high dens residential
retail, commercial
institution, public
recreation
utilities
industry is purple
low d res is yellow
high d res is brown
retail comm is red
institut public is blue
recreation is green
utilities is grey
Metes and Bounds
system or method of describing land, rea
replaced by land ordinance of 1875, which began public land survey system
how many miles in a township
36 square miles
each section has 640 acres
numbered in an s shape
640 acres in a square mile
what is a standard USGS Map
7.5 minute by 7.5 minute, 1:24,000 squale
1 acre in sq ft
43,560 sq ft
1 township in miles
6 miles by 6 miles or 36 sections or 26 sq mile
1 yard in feet in inches, feet and sq ft
36 inches or 3 feet
2 hectare in acres
2.5 acres, roughly a square 100m or 330 ft per side
what are the two basic types of statistical groupings
quantitative and qualitative
what is a grouping of numbers with two or more modes called
bimodal
