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Variables and chi-square in statistics

Pierre Seraphin German 108 cards

difference between population and sample

Cards in this deck (108)

  1. 1What are variablesVariables are properties or characterises of people that vary in quality or magnitude from object to object
  2. 2Exapmles of variablesDemogrihic gender age
    Personality extroverted introverted
  3. 3A variable has tovary be not a constant it must take different values, levels and intensities
  4. 4Variableis any entity that can take on a variety of different values (wrench)
  5. 5DispersionRange
    Deviation
    Abosulute Deviation
    Squared deviation
  6. 6Deviation isthe difference between the value of series and average of serious
    xi-xStrihch
  7. 7Absolute deviation isthe absolute value of D
    AD= /xi-xstiht/
  8. 8Squared deviationSqD is (xi-xstricht)2
  9. 9a modelan abstraction of reality that specifies the important elements to be studied
    Explains what the expected relationships are expected to be between the variables
    Relationship can be a positive or negative
  10. 10Dependent Variables alias Response Variables are the variables of which we want to determine the outcome.Variables of which we want to determine the outcome
  11. 11Independent Variable Explanatroy Variablesare partially explaining the value of the response
  12. 12IVthe variable that is varied or manipulated
  13. 13Dependent variableThe variable in which the response eis measured
  14. 14The higher the income of a student the larger the studio a student is rentingIndependent valiable Income
    Size of the studio
  15. 15Hypothesis: The higher the educational attainment the higher the income.Education is IV and income is the DV
  16. 16Multiple Independent variablesmultiple independent variables affect the dependent variable
  17. 17IVS or XsCountries where citizens are healthy or wealthy will be less like to experience revolution
  18. 18IVs or Xspoverty and bad education will be more likely increase unemployment
  19. 19Describtive vs inferential statisticsdescriptive are statistics that organise summarise and represent data
  20. 20descriptive statisticsfrequency table, central tendency, visualisation graphs, xtab
  21. 21inferential statisticsconsist of techniques by which data is being used to generalise findings, perform hypthiesis test make predictions
  22. 22population or target populationis the entire group of objects or events, we are interested in,
    all people or items withe the characteristic we wish to understand
    the group about we want to draw conclusion
    must be defined in detail
  23. 23SampleIs a subset of the population usually meant to represent the population
    spoon and soup
  24. 24Sample should berepresentative and best done by random sampling
  25. 25difference between population and sampledifference between population and sample
  26. 26how to choose test of significancehow to choose test of significance
  27. 27Chi squaresimple nonparametric test to test the relation ship between categories
  28. 28Chi square nominaldetermines wether the frequencies we observed previously differ significantly from the perfect distribution
    --> Heads tail
  29. 29chi square formulaechi square formulae
  30. 30chi square should be higher than the critical valuecritical value needs is:
    degrees of freedom how many outcome -1
    significance level a
    use the chi square distribution table
  31. 31gendervariable
  32. 32attributemale female
  33. 33logical steps of researchede
    explore
    describe
    explain
  34. 34calvin, length weight hight, distanceratio
  35. 35temperature, celsuius,interveral
  36. 36interval rationcontinious variables
  37. 37ordinal nominaldiscrete values
  38. 38what is a variable?-any entitity that can take different value
    -anything that can vary
    age, country
  39. 39attribute is a specific value on a variableGender has two attributes male and female
    country has the attributes
    Germany Hungary and Greece
  40. 40unit of analysisat the level at which you pitch the conclusion
  41. 41unit of observationat the level at which you collect the data
  42. 42Unit of observation and unit of analysis can be the sameunit of observation can be same but don't have to be.
    unit of observation can be student
    while unit of analysis where you pithc the conclusion
    can be classes
  43. 43what is quantitive research?systematic empirical investigation of observable phenomena through numeric data and statistical techniques
    in order to employ hypotheses and to test and develop theories
  44. 44What two lines of reasoning are there?Deductive (decreasing)
    Indicutive (increasing)
  45. 45Deductivetheory
    hypothesis
    observation
    confirmation
  46. 46InductiveObservation
    pattern
    hypothesis
    theory
  47. 47What is Science ?knowledge concerning general truth and operation of general laws
    through scientific method.
  48. 48Scientists seek to answer two questionsWhat are the facts
    why did the facts come around?
  49. 49what methods do scientists use?in depth interviews, observations, focus grow, content analysis, survey design and experiments
    I look deep in the focus and observe
    makes me content and survey
  50. 50What are the logical steps in political scienceExploration
    Description
    Explanation
  51. 51preliminary task in research will beIdentify: What the nature of the problem is
    Determine: What operationalisation process can be used
    Decide how sample safe selected what research strategy would be best
  52. 52OperationalisationOperationaliszation is the specification of measurable empirical observable phenomena
    to capture an abstract concept
    --> Racism how do u measure racism, happiness, content, wealth etc?
  53. 53validityhow far we measure what we inter to measure
    --> black people more criminal when accounting all crimes committed i a city?
  54. 54reliablity internal consistency consistency over timerelaibitly means that it is stable and we come to the same conclusion over time (consistency over time)
    Internal consistency relaiblity in the sets of question we ask must come be consistent with each other
  55. 55Descriptive vs. Inferential statisticsDescriptive describe and inferential statistics predict
  56. 56Descriptive statisticstechniques by which data are being organised
    summarized
    represented
    Sum of organs is rep
  57. 57Inferential statisticsis technique by which data are being see to generalise findings
    perform hypotestesis tests
    make predictions
  58. 58what types of data are there ?Nominal
    ordinal
    interval
    and ratio
  59. 59Discrete variables arenominal and Ordinal data
  60. 60interval and ratioare continuous variables
  61. 61different datadifferent data
  62. 62ways of presenting numerical data nur große titten numerical graphical and tabularM and M
    Measure of central tendency
    and measure of dispersion
  63. 63tabularfrequency table and corsstabe
  64. 64GraphicalDot plot
    Stem plot
    Pie graph
    Histogramm
    Boxplot
  65. 65Numerical central tendecymiddle,
    Mode,
    Mean,
    Median
  66. 66Central tendencyis a numerical number that describes a set of data by identifying the middle of it
  67. 67Mode Mode kommt am häufigsten vor-value that occurs most often in a dataset
    -works only for nominal data
    -dataset can have more than only one mode
    --> bimodal, or multimodal
    -in case of multiple modes take the smalls one
    -MO
  68. 68mode can be misleadingmode can be misleading
  69. 69mode in a histogramm isthe number with the highest frequency
  70. 70what if multiple modes? or what no mode at all?no mode, all numbers are different
  71. 71histogrammis quantitive
    like bar chart but no gaps
    y represent frequency
  72. 72bimodalis when there are two modes two peaks
  73. 73multiple modalwhen there are more than two modes
  74. 74median is central tendencyordinal number
    median case splits the data into two groups
    md
    MDMA Tablette wird auch in 2 geteilt
  75. 75median number in the middleif not odd numbers than take the two in the middle and sum up and divide
  76. 76median in a histogrammthe bar in the middle
  77. 77meanarithmetic averag
    all numbers summed up and decided by the number of n
    x strich
    for continuous data interval ratio
    suscebtible to outliners
  78. 78skewnessskewness
  79. 79measures of dispersionRange
    Mean
    Variance
    Standard deviation
  80. 80RangeR=H-L
  81. 81Rangeis difference between highest and lowests score
    But great deal of data is neglected
    and very extrem cases are included
  82. 82Msignma /x-xstricht/
    n
  83. 83mean deviationmeasure of variability tha indicates average of deviation from the mean
  84. 84vars2=sigma x-xstricht square
    divide by n
  85. 85standard deviationradical variance
  86. 86standard deviationwill take into account all observations
    in contrast to variance measurement of variability in orginal unit
    standard deviation indicates how far observation differ from the mean
  87. 87what to use whenwhat to use when
  88. 88Spearmanshws strength of correlation between two variables.
  89. 89what is monotonic relationwhat is monotonic relation
  90. 90Spearman Rcan take a value between -1 perfect negative relation
    and +1 a perfect positive relation
    and 0 no correlation at all
  91. 91what is a model my spec ex can be in a positive or negative relationshipa a model is an abstraction of reality that
    --Specifies the important elements to be studtudied
    explains what the expected relationship are between the variables
    if the relationship can be positive or neganegative
  92. 92What is a theory general mechanisma general statement about how the world works that specifies a causal mechanism
  93. 93Hypothesisderived from this theory that makes a specific predictions that can be empirically verified
  94. 94hypothesisfactual claim about association between 2 variables
  95. 95hypothesis:the stronger the labour unions ware in a county the more is spent on welfare
    Independent variable labour unions
    dependent variables amount spent on welfare
  96. 96intervening variable level of education and spening the intervening variable would be incomeis a variable that helps to explain the relationship between two variables
  97. 97bivariate table gender smokingtable that displays distribution of one variable across categories of another
  98. 98regression analysisfind a model to our data that helps to predict the value of a dependent valuable from an independent or multiple independent variables
  99. 99OLS Ordinary least SquareAdvises is tp draw the best fitting line witth the data
  100. 100simple regressionis on predictor variable
  101. 101multiple regressionseveral predictor variables
  102. 102equation for modelsoutcome i = model + error i
  103. 103in a regression line a negative slopenegative relationship
  104. 104regression coefficientregression coefficient
  105. 105what if b1 is 0.233then for every increase in the independent variable we have an increase of 0.233 in the dependent variable
  106. 106Models need to be bluebest
    unbiased
    Estimate
    linear
  107. 107What are possible values for pearsonWhat are possible values for pearson
  108. 108—

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Flashcards on Untitled, created by Pierre Seraphin on 23/01/2016.
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