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Political Science 30 Political Inquiry

Political Science 30 Political Inquiry. Sections meet in Solis 105 this week. Measurement II. Quantifying and Describing Variables. Four Levels of Precision Measures of Central Tendency Mode Median Mean Measures of Dispersion Variance, Standard Deviation.

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Political Science 30 Political Inquiry

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  1. Political Science 30Political Inquiry Sections meet in Solis 105 this week.

  2. Measurement II. Quantifying and Describing Variables • Four Levels of Precision • Measures of Central Tendency • Mode • Median • Mean • Measures of Dispersion • Variance, Standard Deviation

  3. Four Levels of Precision For Measuring Variables (Pollock, p.28) • Nominal Measure: You can put cases into a category, but cannot specify an order or relationship between the categories. • Example: The variable “religion” can take on values such as Catholic, Protestant, Mormon, Jewish, etc.

  4. Four Levels of Precision For Measuring Variables (Pollock, p.28) • Ordinal Measure: You can put cases into different categories, and order the categories. • Example: The variable “strength of religious belief” can take on values such as devoutly religious, fairly religious, slightly religious, not religious.

  5. Four Levels of Precision For Measuring Variables (Pollock, 28-29) • Interval Measure: Not only can you order the categories of the variable, you can specify the difference between any two categories. • Example. The variable “temperature on the Fahrenheit scale” can take on values such as 32 degrees, 74 degrees, 116 degrees.

  6. Four Levels of Precision For Measuring Variables • Ratio Measure: You can order categories, specify the difference between two categories, and the value of zero on the variable represents the absence of the variable. • Example. The variable “annual income” can take on the values of $0, $98,000, or $694,294,129.

  7. Kobe Bryant $24.8 million Pau Gasl $17.8 million Andrew Bynum $13.8 million Lamar Odom $8.2 million Ron Artest $6.3 million Luke Walton $5.3 million Steve Blake $4.0 million Derek Fisher $3.7 million Shannon Brown $2.2 million Matt Barnes $1.8 million Joe Smith $1.4 million Theo Ratliff $1.4 million Devin Ebanks $0.5 million Derek Caracter $0.5 million Measures of Central Tendency(Pollock, Ch. 2)

  8. Measures of Central Tendency(Pollock, Ch. 2) • Mode: The most frequently occurring value. • $1.4 million and $0.5 million • Median: The midpoint of the distribution of cases. • 1. Arrange cases in order • 2. If the number of cases is odd, median is the value taken on by the case in the center of the list. • 3. If the number of cases is even, median is the average of the two center values. $3.85 million

  9. Measures of Central Tendency • Mean is the arithmetic average of the values that all the cases take on. $6.6 million. • Add up all the values • Divide this sum by the number of cases, N.

  10. Measures of Dispersion(Pollock, p.119-124) • The variance is a measure of how spread out cases are, calculated by: • Compute the distance from each case to the mean, then square that distance. • Find the sum of these squared distances, then divide it by N-1. $53.8 million.

  11. Measures of Dispersion(Pollock, pp. 119-124) • The standard deviation is the square root of the variance, $7.3 million.

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