# Shared Flashcard Set

## Details

GEOG 103: Geographic Techniques' Exam II Study Guid
Covers scale of measuremnt, measures of central tendency, measure of variance and dispersion, data classification methods, histogram, weighted mean, Pearson's r, t-values, regression, y-intercept ....
78
Geography
10/10/2013

Term
 What are the 5 scales of measurement?
Definition
 Nominal Enumeration Ratio Interval Ordinal
Term
 How is nominal data classified?
Definition
 variables are qualitative and dsicrete no zero point "in name only"--word or name categories
Term
 How is enumeration data classified?
Definition
 variables are quatitative and discrete  has an absolute zero "to count" whole positive numbers are used to count something
Term
 How is ratio data classified?
Definition
 variables are quantitative and continuous has an absolute zero individuals, cases or observations are placed in a percise numeric position along a continuous scale that begins with a real zero
Term
 How is interval data classified?
Definition
 variables are quantitative and and continuous has an arbitrary zero individuals, cases or observations are placed in a precise numberic position along a continous scale with an arbitrary zero point
Term
 How is ordinal data classified?
Definition
 quantitative data are classified into classes/categories    must be ordered and ranked
Term
 what is the scale of measurement for language?
Definition
 Nominal
Term
 what is the scale of measurement for Social Security number?
Definition
 Nominal
Term
 what is the scale of measurement for age?
Definition
 Ratio
Term
 what is the scale of measurement for age group?
Definition
 Ordinal
Term
 what is the scale of measurement for height?
Definition
 Ratio
Term
 what is the scale of measurement for elevation?
Definition
 Interval
Term
 what is the scale of measurement for temperature class?
Definition
 ordinal
Term
 what is the scale of measurement for number of houses?
Definition
 enumeration
Term
 what is the scale of measurement for number of cars?
Definition
 enumeration
Term
 what is the scale of measurement for number of cars per household?
Definition
 ratio
Term
 what is the scale of measurement for cardinal direction?
Definition
 Nominal
Term
 what is the scale of measurement for economic growth?
Definition
 Interval
Term
 What are the 4 data classification methods?
Definition
 Quantile Breaks Equal Intervals Based on Range Equal Intervals Not Based on Range Natural Breaks
Term
 What are the steps to classifying data?
Definition
 Create a numbler line Analysis true nature of number line Create classes using the four classification methods Divide the numer line into classes by drawing dashed vertical lines Compare classification to true nature of data
Term
 What axis is frequency on?
Definition
 y-axis
Term
 Quantile Breaks/ Quartile Breaks
Definition
 Divide the total number of data value in a data set as equally as possible into four or five classes   objective method => based on the total number of data values, a fixed number
Term
 Equal Intervals Based on Range (EIBR)
Definition
 Divide the range of the data into class intervals of equal size   objective method => based on the range of the data, a fixed number
Term
 Equal Intervals Not Based on Range (EINBR)
Definition
 artificially expand the range 1 to 3 increments   equally divided the expanded range   limited subjectivity => researcher chooses how much to expand
Term
 Natural Breaks
Definition
 use natural breaks in frequency/distribution of data on the number line   3 to 7 significant breaks   most subjective
Term
what kind of data and graph? Definition
 nomical/discrete data histograph
Term
What kind of data and graph? Definition
 Ratio/ordinal/continuous data   historgram
Term
 What is a historgram?
Definition
 A bar graph that displays data values or classes along the x-axis and their frequencies on the y-axis
Term
 How is height determined on a histogram?
Definition
 By the frequency of that data value or class
Term
 When are the bars connected in a histogram?
Definition
 When the data is continuous
Term
 When are the bars disconnected in a histogram?
Definition
 When the data is discrete
Term
 What are the three measures of central tendency?
Definition
 Mode Median Mean
Term
 What is the mode?
Definition
 The most frequently occuring data value(s)  in a data set
Term
 When does a mode occur?
Definition
 When a value occurs at least 3 or more times in a data set
Term
 What is a biomodal?
Definition
 Two distinctly different data values with the greatest frequency in a data set
Term
 For what data should the mode be used?
Definition
 Nominal (mode is only measurement of central tendency)     Can also be used for: enumeration, ratio, interval, and ordinal data
Term
 How is the mode found in ordinal (classified) data?
Definition
 Located in inside the class with the largest frequency and is the midpoint of that class
Term
 What is the median?
Definition
 The middle value from a data set
Term
 For what data should the median be used?
Definition
 Enumeration Ratio Interval
Term
 What are the steps needed to take to find the median?
Definition
 Put data in numerical order Find midpoint(s) If there are 2 midpoints, then find average of the 2 #s
Term
 What is the mean?
Definition
 The average value of a data set calculated by summing the values of a data set, and then dividing this sum by the number of observations in the data set
Term
 THe mean is used for what data?
Definition
 Enumeration Ratio Interval
Term
 Sample Mean Formula
Definition
 [image]
Term
 Population Mean formula
Definition
 [image]
Term
 What is the weighted mean?
Definition
 A statistical formula that computes the mean of a variable whose data have been classified
Term
 Weighted Mean formula
Definition
Term
 The weighted mean is used for what data?
Definition
 ordinal
Term
 What is the Fj in the weighted mean formula?
Definition
 Frequency of the specific class
Term
 What is Xj in the weighted mean formula?
Definition
 the midpoint/average of each class interval
Term
 How to calculate the weighted mean :
Definition
 Find the average/midpoint for each class then multiply the class frequency by the class average for EACH CLASS = Xj * Fj Add together  Xj * Fjof each class Divide the sum of Xj * Fj of each class by sum of the frequencys of all the classes
Term
 What factor determines the appropriate measure of central tendency?
Definition
 the symmetry of the data/ frequency distribution
Term
 What is a normal (symmetrical) frequency distribution?
Definition
 THe values of your data set are distributed fairly evenly on both sides of the mean of the data
Term
 Where is the mode, median, and mean located on the distribution curve?
Definition
 Center of a distribution curve
Term
 What is a skewed distribution?
Definition
 The data values are distributed unevenly on both sides of the mean of the data
Term
 What is a positive skew?
Definition
 The greatest frequency of the data occurs toward the low end of the range       The mean of the data values is pulled away from the area of the greatest frequency toward the right (positive) direction of the x-axis by a few high values in the data set
Term
 What is a negative skew?
Definition
 The greatest frequency of the data occurs toward the high end of the range               The mean of the data is toward the left (negative)
Term
 What measures of central tendency can be used for a normal distribution?
Definition
 ALL  THREE--mode, median, mean
Term
 What measures of central tendency can be used for a skewed distribution?
Definition
 Mode and Median
Term
 What measures of central tendency can be used for an extremely skewed distribution and bimodal?
Definition
 Mode
Term
 What do measures of dispersion and variability tell you?
Definition
 They provide an indication of the degree to which data values are distributed to either side of their mean
Term
 What is the range?
Definition
 The difference between the largest and smallest data values
Term
 What is standard deviation?
Definition
 Based on individual deviations of each data value in a data set from their mean
Term
 Sample Standard Deviation
Definition
 [image]
Term
 Population Standard Deviation
Definition
 [image]
Term
 What is the coefficient of variation?
Definition
 A realtive measure (percentage) of dispersion and variability
Term
 In what circumstances should the coefficient of variation be used?
Definition
 When comparing standard deviations between geographic regions When comparing the standard deviations of two or more variables with different measurement units when comparing the standard deviation of two or more variables whose data values are significantly different in magnitude
Term
 Coefficient of Variation (sample) Formula
Definition
 [image]
Term
 Coefficient of Variation (population) Formula
Definition
 [image]
Term
 What does Pearson Correlation Coefficient (pearsons r) determine?
Definition
 The strength of a relationship between two variables
Term
 What does the "t test" determine?
Definition
 If Pearson's R is statistically significant if we can rely on pearsons r
Term
 Pearsons R Correlation Coefficient Formula
Definition
 [image]
Term
 Degrees of freedom
Definition
 One degree of freedom is subtracted for each variable
Term
 How to test for statistical significance:
Definition
 Calculate pearsons r Calculate t-test Use t-test and degrees of freedom to find the critical value Compare the t-test to the critical value: must be equal to or greater than the critical value
Term
 T-test formula
Definition
 [image]
Term
 Coefficient of Determination Formula
Definition
 coefficient of determination = r2 * 100
Term
 Regression formula
Definition
 y = a + bx
Term
 slope formula (b)
Definition
 [image]
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