class 6, 10/15/12

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• class 6, 10/15/12
• intro to statistical methods

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• research is
• research is systematic self-critical inquiry made
  public (Lawrence Stenhouse, 1981)
• challenging accepted or received knowledge
  (Alfred North Whitehead)
• figuring out what the devil people think they are
  up to (Geertz)
• copy from one, its plagiarism copy from many,
  its research (Wilson Mizner)

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• dimensions of research
• proximity
• face-to-face...distanced
• duration
• intermittent...field-based
• description
• measurement.narrative
• theory
• building.......testing

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• preferences cont.
• Inventor Thomas Edison had a simple test he used
  to measure the unexpectedness quotient of
  prospective employees. He would invite a
  candidate to lunch and serve a bowl of soup. He
  would then watch to see whether the person salted
  his soup before tasting it. If he did, he
  wouldn't be offered the job. Edison felt that
  people are more open to different possibilities
  if they don't salt their experience of life
  before tasting it.
• Von Oech, Roger. (2002). Expect the unexpected or
  you
• won't find it. San Francisco Berrett-Koehler.

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an introduction to statistics
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• brief history
• statistics from the same root as state
• first use of statistics was descriptiveto
  describe by counting matters of importance to the
  State, e.g., census
• inferential statistics began with the study of
  probabilities
• once people understood probabilities of an event
  given certain conditions, they began to realize
  that they could make inferences from a sample to
  population

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• computational shortages and bottlenecks across
  time (in the West)
• paper mathematicians learned to develop
  shortcuts, complex algorithms
• roman numerals incredibly clumsy
• CXCVIII XLIV
• no zero
• time (pre-calculating machines) development of
  more shortcuts and algorithms

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• time (hand calculating machines)
• computer speed, memory, money (mainframes)
  algorithms and clever ways to trick computers
• clumsy software, memory, speed (first PCs)
• imagination with fast computers and unlimited
  memory, only constraint is how to use them

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• some people in the history of statistics
• Karl Pearson (1857-1936)
• Ronald Fisher (1890-1962)
• William Gosset (Student) (1876-1937)
• Prasanta Chandra Mahalanobis (1893-1972)
• Andrei Kolmogorov (1903-1987)
• John Tukey (1915-2000)
• Jerzy Neyman (1894-1981)
• Gertrude Cox (1900-1978)
• F(lorence) N(ightingale) David (1909-1995)

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• some moments in history of statistics
• 1908 Students t-test
• 1915 distribution of the correlation coefficient
  (Fisher)
• 1925 Statistical methods for research workers
  (Fisher)
• 1931 Founding of Indian Statistical Institute
  (Mahalanobis)
• 1934 proof of the central limit theorem (Levy,
  Lindeberg)
• 1935 The design of experiments (Fisher)

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• 1945 nonparametric tests (Wilcoxon)
• 1947 Mann-Whitney formulation of nonparametric
  tests
• 1959 definitive formulation of hypothesis
  testing (Lehmann)
• 1970 Games, gods, and gambling (F. N. David)
• 1977 Coxs formulation of significance testing
• 1977 Exploratory data analysis (Tukey)

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• Pearsons 4 parameters
• mean
• standard deviation
• symmetry
• kurtosis
• Parameters are not numbers like measurements.
  They can never be observed but can be inferred by
  how the measurements scatter. Parameter comes
  from the Greek for almost measurements.
• Salsburg, D. (1981).The lady tasting tea. New
  York, NY Henry Holt.)

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• normal distribution (bell-shaped curved)
• many things in the world distributed normally
• many statistics distributed normally
• in normal distributions only 2 parameters
• mathematically, normal distributions, compared to
  many other distributions, easy to work with

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• Krathwohl, ch 17 descriptive statistics
• description by measurement
• nominal
• 1 freshman, 2sophomores etc
• ordinal
• 1 Gretsky 2Howe, 3Hull, 4 Crosby, etc
• interval
• fahrenheit scale
• ratio
• metric scale, eg, distance

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• graphic representation of data
• to convey the greatest number of ideas in the
  shortest time with the least ink in the smallest
  space

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• measures of central tendency
• mode measure that appears most often
• e.g., survey of favorite restaurants
• median middle score
• e.g., baseball players salaries
• mean average
• well behaved data

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• skewness asymmetry in distribution
• tail to right positive skew (mean largest, then
  median, then mode)
• can be due to floor effect
• tail to left negative skew (mean smallest, then
  median, then mode)
• can be due to ceiling effect

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• measures of dispersion variability
• range distance from highest to lowest
• standard deviation and variance average distance
  of each observation from mean (and average
  distance squared)

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• standard score (z-score) raw score translated
  into distance from mean in SD units
• derived (scale) score translates standard scores
  into scale where all scores positive
• stanine (standard nine) half a SD

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• in a normal distribution
• 68.26 of the cases within 1 SD either side of
  the mean
• 95.44 within 2 SDs
• 99.74 within 3SDs

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• measures of relationships
• correlation (Pearson product-moment) strength of
  relationship, -1 to 1
• positive as one measure gets larger (or
  smaller), so does the other
• negative as one measure gets smaller, the other
  gets larger (or vice versa)
• effect of outliers (see figure 17.9)
• effect of range (see figure 17.10. 17.11)
• effect of nonlinearity (see figures 17.9 17.12)

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• always
• plot
• your data
• look at the plot
• most carefully

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• correlation and causation
• no statistical relationship necessarily implies
  causation
• other correlations for special conditions (beyond
  the scope of this course)
• treatment of outliers
• be careful and be honest

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• interpreting statistics
• were analyses appropriate
• were assumptions underlying analyses met
• was sample representative
• look carefully at the data and what underlies
  them
• exploratory data analysis (Tukey, 1977)
• perfectly legitimate, and important, but
  conclusions or hypotheses that result should be
  tested with another data set

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• thinking
• reaction time speed
• .7 1.43
• .8 1.25
• .9 1.11
• 1.0 1.0
• 1.1 .91
• 1.2 .83
• 1.4 .71
• 1.5 .67
• 1.6 .62
• .10
• .05
• M 3.65 .79

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• birthday problem
• p 1-(365)! / (365-k)!365k
• K p
  
• 5
  .027
• 10
  .117
• 15
  .253
• 20
  .411
• 22
  .476
• 23
  .507
• 25
  .569
• 30
  .706
• 40
  .891
• 50
  .970
• 60
  .994
• 100
  .9999997

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• Ethics
• Sieber, ch. 5 Privacy
• 5.1
• privacy
• confidentiality
• anonymity
• 5.2
• the subtlety of privacy issues
• 5.3 the right to privacy
• Hatch Act

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• 5.4 behavioral definition of privacy
• 5.5 privacy and informed consent
• 5.6 sensitivity
• ask someone who works with population
• ask researchers who work with population
• ask member of population
• 5.7 brokered data

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• Becker ch 3
• Researchers have to organize their material,
  express an argument clearly enough that readers
  can follow their reasoning and accept the
  conclusions. They make this job harder than it
  need be when they think that there is only One
  Right Way to do it, that each paper has a
  preordained structure they must find. They
  simplify their work, on the other hand, when they
  recognize that there are many effective ways to
  say something and that their job is only to
  choose one and execute it so that readers will
  know what they are doing. (p. 43)

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• some writing tips
• write introductions last (p. 50)
• put the conclusion at the beginning (p. 52)
• evasive vacuous sentences a good way to begin
  early drafts
• any sentence can be changed, rewritten, or
  contradictedyou can write anything at all (p.
  54)
• begin with a spew draft (p. 55)
• give thoughts a physical embodimentget them on
  paper (p. 56)

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• tips cont.
• outlines can help, but not if you begin with them
  (p. 60)
• do what is easiest first (p. 60)
• talking about them, instead of just wishing them
  away, solves all sorts of scientific problems,
  not just those of writing (p. 64)
• tips not from Becker
• write conclusion first
• never start a paper at the beginning
• writing not a linear process

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• APA hints
• heading levels (62-63)
• Centered, Bold, Upper, Lower
• Flush Left, Bold, Upper, Lower
• Indented, bold, lower paragraph heading ending
  with period.
• Indented, bold, italics, lower paragraph
  heading ending with period.
• Indented, italics, lower paragraph heading
  ending with period.

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• Contemporary Realities (1)
• Cronbach (1975) observed, It is the
  special task of the social scientist in each
  generation to pin down contemporary factsand
  to realign cultures view of people with
  present realities (p. 126). Educational
  researchers study people interacting in culture.
  The realities we encounter daily continually
  change. . . .
• Other Peoples Children (2)
• The most salient contemporary reality
  affecting early education and care in
  contemporary post-industrial societies is that
  increasingly large segments of these societies
  have given over the raising of their young
  children, from an increasingly early age, to
  others. At one time, only the rich did not raise
  their own children. Now, the large majority of
  children are being raised by others. Giving ones
  children to others to raise is a new phenomenon
  for the working and middle classes.
• Increasing numbers. (3) According to
  the US Department of Education National Center
  for Education Statistics, 57 of children age 3-5
  in the US are in some kind of institutional early
  childhood care and education program. For
  children of mothers with college degrees or
  higher, the percentage rises to 73. The
  percentage of children from 3-5 in at least one
  weekly non-parental care arrangements, which
  includes, in addition to institutional care,
  informal out-of-the-home care, for example, with
  baby sitters or relatives, or children in
  unlicensed day cares, rises to 73.
• Institutional care. (4) Children in
  institutional care range . . . .

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• comma (78-80)
• between elements in a series (3 or more)before
  and or or (Harvard comma)
• the height, width, and depth
• to set off nonessential or nonrestrictive clause
• John, who loved his wife, was the key informant.
• to separate 2 independent clauses joined by a
  conjunction (e.g., but, and, for, yet etc)
• John loved Angela, but Angela loved Rashad.

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• to set off year in exact dates
• April 18, 1992, Masatoshi left.
• April 1992 Masatoshi left.
• to set off year in citations (in parens)
• (Hatano, 1998)
• in numbers 1,000 or more

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• do not use commas
• to separate compound verbs
• I hit the ball, and ran to first base. (wrong)
• I hit the ball and ran to first base. (correct)
• I hit the ball, and I ran to first base.
• to separate the subject from the verb
• The young woman in the second row in the blue
  dress and red hat, raised her hand to ask a
  question. (wrong)
• Miranda, who was sitting in the second row and
  was wearing a blue dress and red hat, raised her
  hand. (correct)

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• Vogt
• nominal scale
• operational definition
• outlier
• parsimony
• path diagram
• practical significance
• Pygmalion effect

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• more goods
• good free music
• Krannert Uncorked, most thursdays, 5pm
• student and faculty performances, Smith Hall and
  Krannert (see Inside Illinois)
• good place to prepare for Halloween
• Dallas Company, 1st University, C
• good used book stores
• Jane Addams, 208 N. Neil C
• Old Main Book Shop, 116 N Walnut C
• Priceless Books, 108 W Main U

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• Asian grocery stores
• Lees, next to County Market on Kirby, C
• Far East, 5th St south of University, C
• AmKo, 1st and Springfield, C
• Green Onion, 2020 S. Neil, C

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• directions to Homer Lake
• take Washington in U east.
• a few miles east of Urbana, road will end. Turn
  right, then the first left.
• a few more miles road will jog right then left
• a few more miles, road will turn into county
  highway. continue east.
• about 15 miles out, you will see wooded area to
  right, housing development to left.
• cross bridge over a channelbit of lake to right,
  
• continue a few hundred yards to first paved road
  to rightsmall sign Salt Fork Forest Preserve
• turn right, continue about ¼ mileentrance to
  Homer Lake.