Thinking about Data:

• Terms:– matrix– unit of analysis– case– variable – code

Types of Data

• Microlevel: data collected on the characteristics of individual cases, people, houses, events, that is, discrete units. For example an individual, with characteristic information on sex, age, state of residence, etc.

• Aggregate: Tabular data representing counts of units falling into particular categories, e.g., populations of states. The state is the unit of analysis; the variables are the name of the state and the population of the state.

Sources of Data

• Survey: collected specifically for the research purpose, e.g., CPS, GSS, census.

• Administrative record: records of immigrant arrivals by port; tax filings; vital registration records; case files of judicial proceedings, health records.

Univariate Statistics

• Types of Variables: Nominal; ordinal, interval, ratio

• Measures of central tendency: mean, median, mode

• Measures of dispersion: standard deviation, ntiles, range, coefficient of variation

• Measures of shape: skewness, kurtosis.

STATS YRBUILT CONCOST / Mean Min Max SD STATS YRBUILT CONCOST / Mean Min Max SD CV Kurtosis Median Range SEK SEM SES CV Kurtosis Median Range SEK SEM SES

Skewness Sum Variance N CIM=.95Skewness Sum Variance N CIM=.95• YRBUILT• N of cases 1235• Minimum 888.000• Maximum 929.000• Range 41.000• Sum 1116660.000• Median 904.000• Mean 904.178• 95% CI Upper 904.724• 95% CI Lower 903.633• Std. Error 0.278• Standard Dev 9.770• Variance 95.451• C.V. 0.011• Skewness(G1) 0.409• SE Skewness 0.070• Kurtosis(G2) -0.528• SE Kurtosis 0.139

• CONCOST

• 1127• 20.000• 5200.000• 5180.000• 354277.000• 250.000• 314.354• 332.888• 295.820• 9.446• 317.116• 100562.250• 1.009• 5.563• 0.073• 59.859• 0.146

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