Term

Definition
 Research that derives its data from direct observation or experiment
 To answer sociological research questions we cannot rely on reasoning, speculation, moral judgment, or subjective preference.
 EX: "What is the prevalence of binge drinking on college campuses?



Term

Definition
 Requires judgment
 ex: "is binge drinking the most serious problem facing college campuses today?"



Term

Definition
 theory an explanation of the relationship between two or more observable attributes of individuals or groups



Term

Definition
 used by social scientists to establish a link between what we observe(the data) and our understanding of why certain phenomena are related to each other in a particular way.



Term

Definition
 tentative answers to research questions (subject to empirical verification) that are derived from theories
 a statement of relationship betwen characteristics that vary (variables)



Term

Definition
 Population the total set of individuals, objects, groups, or events in which the researcher is interested.



Term

Definition
 Sample a relatively small subset selected from a population
 We use samples to draw inferences about populations



Term

Definition
 Variables a property of people or objects that takes on two or more values that indicates a concept in the real world.



Term

Definition
 Dependent variable The variable to be explained (the "effect")
 The dependent variable is what you are trying to explain



Term

Definition
 Independent variable the variable expected to account for (the "cause" of) the dependent variable.
 Usually occurs earlier in time than the dependent variable.
 The independent variable influences, directly or indirectly, the dependent variable.
 The value of the dependent variable depends on the value of the independent variable



Term
Nominal level of measurement 

Definition
 numbers or other symbols are assigned toa set of categories for the purpose of naming, labeling, or classifiying the observations
 Examples:
 Political party (democrat, republican)
 Religion (Catholic, Jewish, Muslim, Protestant)
 Race (African Americann, Latino, Native American)



Term
Ordinal level of measurement 

Definition
 Nominal variables that can be ranked from low to high (IN AN ORDER)
 Example: College Class
 Freshman
 Sophomore
 Junior
 Senior



Term
Intervalratio level of measurement 

Definition
 Variables where measurements for all cases are expressed in the same units. Will also be a "pretty exact/specific" number. (Variables with a natural zero point, such as height and weight, are called ratio variables)
 Examples:



Term

Definition
 Ratio variables Variables with a natural zero point, such as height and weight



Term

Definition
 variables that have a minimumsized unit of measurement, which cannot be subdivided
 EX: the number of children per family



Term

Definition
 variables that, in theory, can take on all possible numerical values in a given interval
 EX: length



Term

Definition
 Procedures that help us organize and describe data collected from either a sample or a population.
 What is there
 EX: average age, proportion of males and females in population



Term

Definition
 the logic and procedures concerned with making predictions or inferences about a population from observations and analyses of a sample.
 saying something about the sample then saying how it reflects an entire population
 EX: average exam grade from 10 randomly drawn students in the class



Term
Frequency distribution
(definition and how to create them) 

Definition
 frequency distribution A table reporting the number of observations falling into each category of the variable
 how to create:
 1 tally results
 2 count frequencies



Term

Definition
 a relative frequency obtained by dividing the frequency in each category by the total number of cases
 P=f/N (expressed in 0.___ form)
 Proportions and percentages are relative frequencies.



Term

Definition
 a relative frequency obtained by dividing the frequency in each category by the total number of cases (proportion) and multiplying by 100.
 (%) = p x 100
 Proportions and percentages are relative frequencies.



Term

Definition
 A table showing the percentage of observations falling into each category of the variable.



Term
Cumulative Frequency Distribution 

Definition
 A distribution showing the frequency at or below each category (class interval or score) of the variable



Term
Cumulative Percentage Distribution 

Definition
 A distribution showing the percentage at or below each category (class interval or score) of the variable.



Term

Definition
 A number obtained by dividing the number of actual occurrences in a given time period by the number of possible occurrences.
 EX: Number of people in U.S. prisons and jails
 incarceration rate= #incarcerated
 Population size
 *Be sure to look at day 3 notes at the last 2 slides*



Term

Definition
 A graph showing the differences in frequencies or percentages among categories of a nominal or an ordinal variable. The categories are displayed as segments of a circle whose pieces add up to 100 percent of the total frequencies.
 *When there are too many categories, the smaller categories can be reduced into a sort of "miscellaneous" category



Term

Definition
 A graph showing the differences in frequencies or percentages among categories of a nominal or an ordinal variable. The categories are displayed as rectangles of equal width with their height proportional to the frequency or percentage of the category.
 Ex: could be one bar column for "married people" or can display more by having a "married males" and "married females" columns right next to each other



Term
Statistical Map (def)
&
Geographical Variations in Variables(def) 

Definition
 Statistical map displays dramatic geographical changes in a society
 Geographical Variations in Variables like population distribution, voting patterns, crimes rates, or labor force participation.



Term

Definition
 a graph showing the differences in frequencies or percentages among categories of an intervalratio variable. The categories are displayed as contiguous bars, with width proportional to the width of the category and height proportional to the frequency or percentage of that category.



Term

Definition
 A graph showing the differences in frequencies or percentages among categories of an intervalratio variable. Points representing the frequencies of each category are placed above the midpoint of the category and are jointed by a straight line.



Term

Definition
 A graph displaying changes in a variable at different points in time. It shows time (measured in units such as years or months) on the horizontal axis and the frequencies (percentages or rates) of another variable on the vertical axis.



Term
Measure of Central Tendency 

Definition


Term

Definition
 The category or score with the largest frequency (or percentage) in the distrubtion
 The mode can be calculated for variables with levels of measurement that are: nominal, ordinal, or intervalratio



Term

Definition
 The score that divides the distribution into two equal parts, so that half the cases are above it and half below it.
 The median is the middle score, or average of middle scores in a distribution
 Can be calculated for ordinal or interval level variables
 Middle case= (N+1)/2



Term

Definition
 The arithmetic average obtained by adding up all the scores and dividing by the total number of scores.
 Formula: Y bar= (sigma Y)/N
 Formula to calculate mean w/grouped scores:
 Y bar= (sigma (f)(Y))/N Where (f)(y)= a score multiplied by its frequency



Term
The measures that can be used with
nominal, ordinal, and intervalratio variables 

Definition
 Nominal variable the mode is the only measure that can be used.
 Ordinal variables the mode and the median may be used. The median provides more information (taking into account the ranking of categories)
 Intervalratio variables the mode, median, and mean may all be calculated. The mean provides the most information about the distribution, but the median is preferred if the distribution is skewed.



Term

Definition
 Symmetrical mean is about equal to median
 Skeweda few extreme values on one side of the distribution shift the distribution
 Negatively mean ex:children per household
 Positively mean>median ex: income
 Bimodal two distinct modes
 Multimodal more than 2 distinct modes
*Refer to last slide on day 5 notes to view visual graphs 


Term

Definition
 Numbers that describe diversity or variability in the distribution
 Measures of variation reveal how far from the typical or central score that the distribution tends to vary



Term
Index of Qualitative Variation
(IQV) 

Definition
 A measure of variability for nominal variables. It is based on the ratio of the total number of differences in the distribution to the maximum number of possible differences within the same distribution.
 IQV ranges 01. 0=no diversity.1=maximum diversity (evenlydistributed)
 IQV=K(100^{2} Σf^{2})/100^{2}(K1)
 K=# of categories
 N =total # of cases in the distribution
 Σf^{2=}the sum of all the squared frequencies or percentages



Term

Definition
 A measure of variation in intervalratio variables. It's the difference between the highest (max) and the lowest (min) scores in the distrib.



Term
InterQuartile Range (IQR) 

Definition


Term

Definition

Graphic device that visually presents the following elements: the range, the IQR, the median, the quartiles, the minimum (lowest value) and the maximum (highest value)



Term
Variance (def) and Standard Deviation (def) 

Definition


Term
Measures of variables that can
use IQV or IQR 

Definition

Nominal variables can only use IQV

Ordinal variables can calculate the IQV or the IQR

Intervalratio variables can use IQV, IQR, or variance/standard deviation. Standard deviation provides most info, since it uses all the values in the distrib in its calc.


