Chapter 8: Elementary Quantitative Data Analysis

Question 1

Quantitative data analysis

Answer 1

Statistical techniques used to describe and analyze variation in quantitative measures

Question 2

Statistic

Answer 2

a numerical description of some feature of a variable or variables in a sample from a larger population

Question 3

Descriptivie statistics

Answer 3

Statistics used to describe the distribution of and relationship among variables

Question 4

Inferential statistics

Answer 4

Statistics used to estimate how likely it is that a statistical result based on data from a randoms ample is representative of the population from which the sample is assumed to have beeen selected

Question 5

Data cleaning

Answer 5

The process of checking data for errors after the data have been entered in a computer file

Question 6

Central tendency

Answer 6

The most common value (for variables measured at the nominal level) or the value around which cases tend to center (for a quantitative variable

Question 7

Variability

Answer 7

The extent to which cases are spread out throught he distribution or clustered around just one value

Question 8

Skewness

Answer 8

The extent to which cases are clustered more at one or the other end of the distribution of a quantitative variable rather than ina symmetric pattern around its center. Skew can be positive (a right skew), witht he number of cases tapering off in the positive direction, or negative (a left skew), with the number of cases tapering off in the negative direction

Question 9

Three features in describing the shape of the distribution

Answer 9

1. Central Tendency
2. Variability
3. Skewness

Question 10

Bar chart

Answer 10

A graphic for qualitative variables in which the variable’s distribution is displayed with solid bars separated by spaces

Question 11

Histogram

Answer 11

A graphic for quantitative variables in which the variable’s distribution is displayed with adjacent bars

Question 12

Frequency polygon

Answer 12

A graphic for quantitative variables in which a continuous line connects data points representing the variable’s distribution

Question 13

Frequency distribution

Answer 13

Numerical display showing the number of cases, and usually the percentage of cases (the relative frequencies), corresponding to each value or group of values of a variable

Question 14

Percentage

Answer 14

The relative frequency, compute by dividing the frequency of cases in a particular category by the total number of cases and multiplying by 100

Question 15

Base number (N)

Answer 15

The total number of cases in a distribution

Question 16

Mode (probability average)

Answer 16

The most frequent value in a distribution; also termed the probability average

Question 17

Bimodal

Answer 17

A distribution in which two nonadjacent categories have about the same number of cases and these categories have more cases than any others

Question 18

Unimodal

Answer 18

A distribution of a variable in which only one value is the most frequent

Question 19

Median

Answer 19

The position average, or the point, that divides a distribution in half (the 50th percentile)

Question 20

Mean

Answer 20

The arithmetic, or weighted, average compute by adding the value of all the cases and dividing by the total number of cases

Question 21

Range

Answer 21

The true upper limit in a distribution minus the true lower limit (or the highest rounded value minus the lowest rounded value, plus 1)

Question 22

Outlier

Answer 22

An exceptionally high or low value in a distribution

Question 23

Interquartile range

Answer 23

The range in a distribution between the end of the 1st quartile and the beginning of the 3rd quartile

Question 24

Quartiles

Answer 24

The points in a distribution corresponding to the first 25% of the cases, the first 50% of the cases, and the first 75% of the cases

Question 25

Variance

Answer 25

A statistic that measures the variability of a distribution as the average squared deviation of each case from the mean

Question 26

Standard deviation

Answer 26

The square root of the average squared deviation of each case from the mean

Question 27

Normal distribution

Answer 27

A symmetric distribution shaped like a bell and centered around the population mean, with the number of cases tapering off in a predicatable pattern on both sides of the mean

Question 28

Cross-tabulation (crosstab)

Answer 28

In the simplest case, a bivariate (two-variable) distribution showing the distribution of one variable for each category of another variable; can also be elaborated using three or more variables

Question 29

Measure of association

Answer 29

A type of descriptive statistic that summarizes the strength of an association

Question 30

Gamma

Answer 30

A measure of association that is sometimes used in cross-tabular analysis

Question 31

Chi-square

Answer 31

An inferential statistic used to test hypothese about relationships between two or more variables in a cross-tabulation

Question 32

Statistical significance

Answer 32

The mathematical likelihood that an association is not the result of chance, judged by a criterion the analyst sets (often that the probability is less than 5 out of 100, or p

Question 33

Extraneous variable

Answer 33

A variable that influence influences both the independent and dependent variables to create a spurious association between them that dissappears when the extraneous variation is controlled

Question 34

Elaboration analysis

Answer 34

The process of introducing a third variable into an analysis to better understand - to elaborate - the bivariate (two-ovariable) relationship under consideration; additional control variables also can be introduced

Question 35

Secondary data analysis

Answer 35

The method of using preexisting data in a different way or to answer a different research question that intended by those who collected the data

Question 36

Secondary data

Answer 36

Previously collected data that are used in a new analysis

Question 37

Big data

Answer 37

Data produced or accessible in computer-readable form that is produced by people, available to social scientists, and manageable with today’s computers

Question 38

Ngrams

Answer 38

Frequency graphs produced by Google’s database of all words printed in more than one third of the world’s books over time (with coverage still expanding).