Exam 1

**Elements of the research process**

* Develop a research question
* Review the literature and formulate hypotheses
* Collect data
* Analyze the data
* Evaluate the hypothesis

**Theory**

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

**Hypothesis**

relates two observable attributes to one another in a causal manner

**Qualitative**

measurements for which there is no natural numerical scale, but which consist of __attributes, labels, or other non-numerical characteristics__

**Quantitative**

numerical measurements that arise from a natural __numerical__ scale

**Generalize**

statistically calculating the likely parameters of a population using data from a random sample of that population

**Unit of Analysis**

the major entity that is being analyzed in a study

**Variables**

attributes of a unit that can change from one case to another

**Dependent Variable**

the variable the researcher wants to explain (outcome)

**Independent Variable**

the variable that is thought to produce the effect (factor, cause)

**N**ominal

unordered categories measuring differences in kind rather than amount. has no hierarchy

**O**rdinal

ordered categories with attributes that can be logically rank-ordered

**I**nterval-**R**atio

Numeric variables that can be ranked hierarchically. Distance between each attribute can be quantified

**Discrete variables**

variables that can be counted in units that are not reducible into smaller units

**Continuous variables**

variables that can be subdivided into increasingly small values

**Dichotomous Variable**

Can only take one of two mutually exclusive values (ex: yes/no)

**Population**

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

**Sample**

subset of a population in a study

**Descriptive Statistics**

describe or summarize sample data

**Inferential Statistics**

determining whether the relationships found in a sample can be generalized to the entire population

**Univariate Statistics**

examine only one single variable, in isolation from other variables

**Bivariate Statistics**

examine the relationship between two variables

**Multivariate Statistics**

examine the relationship between more than two variables

**Frequency Distributions**

* Describes a variable by telling us how many and what percentage of respondents fall into a particular category/value or range of values
* Describes both the average response and the variation

**Frequency**

the number of respondents in a particular category or with a particular value

**Proportion**

frequency/total number of respondents (N)

**Percent**

proportion \* 100

**Cumulative Percent**

the percent of respondents who are at or “below” a given category

**Cumulative Distributions**

Shows the frequencies at or below each level of a variable

**Rates**

a number obtained by dividing the number of actual occurrences in a given time period by the number of possible occurrences

Univariate Graphs

graphs showing the distribution of respondents across values or categories of a single variable

Bivariate Graphs

graphs showing the distribution of respondents across values or categories of two variables at the same time

**Time-series chart**

A graph that displays change in a variable at different points in time. It shows time on the horizontal axis, and frequencies or percentages of a variable on the vertical axis

Nominal and ordinal variables graph types

Bar graphs, pie charts, or statistical maps

Interval-ratio variables graph types

Histograms, frequency polygons, or statistical maps

**Descriptive Statistics**

Measures of central tendency (incl. mean, median, mode) and measures of dispersion (Allow us to describe how much variation there is in the distribution (i.e., how much difference is there between cased))

**Positively Skewed**

If the mean is higher than the median, which is higher than the ode, the distribution is skewed to the right (high point on the left of the curve)

**Negatively Skewed**

If the mean is lower than the median, which is lower than the mode, the distribution is skewed to the left (high point on the right of the curve)

**Variance**

Provides a simple summary for describing the total deviation from the mean

**Coefficient of Variation**

ratio of the standard deviation to the mean