Quantitative Research

Bivariate

Of, relating to, or involving two variables.

BoxPlot

Provides a visual representation of central tendency and dispersion. Graphs the median, range, and interquartile range.

Central Tendency

The most typical, central, or common score of a variable. Measured via mode, median, and mean.

Coefficient of Deviation (CV)

The ratio of the standard deviation to the mean. Is used when comparing variables with different scales.

Concurrent Validity

A type of measurement of validity. Compares how a new test or assessment aligns with a currently accepted, already validated test.

Construct Validity

A type of measurement of validity. Assesses the degree to which a test or other measure assesses the underlying theoretical construct it is supposed to measure.

Continuous Variables

A type of numerical variable that can take on any value within a given range.

Control Variables

A variable the researcher assumes influences the dependent variable, and thus is controlled for when testing the relationship between the independent and dependent variables. An extraneous variable that is controlled for.

Convergent Validity

A measurement of validity. Assesses the degree to which two measures that are supposed to measure the same or similar concept produce similar results.

Data

Numerical information/what you find as a result of your experiment or survey.

Deductive Reasoning

Top down reasoning. Researchers start with a theory and then operationalize the theory/hypothesis through various measurements, assessments, and statistical tests.

Dependent Variable

A measure of the effect of the independent variable. The outcome.

Dispersion

The variety, diversity, or amount of variation between scores. Measured commonly via index of qualitative variation, range, and interquartile range.

External Validity

A measurement of validity. Assesses the extent to which a study’s results can be generalized to other people, settings, and times.

Face Validity

A measure of validity. Concerned with whether a measure seems relevant and appropriate for what it’s assessing on the surface.

Frequency Distribution

A table or graph that shows how often values occur in a dataset.

Generalization

A goal of quantitative research. How applicable the findings are to those not studied.

Histogram

A visual/graphical representation of a dataset’s frequency distribution.

Hypothesis

A testable statement of claim.

Independent Variable

The variable that is controlled or manipulated by the researcher in accordance with the purpose of the investigation. Can also be the variable that is predicted to do the affecting.

Index of Qualitative Variation (IQV)

Used when measuring nominal or ordinal variables. The ratio of “actual variation” to “maximum possible variation” in a distribution.

Inductive Reasoning

Bottom up reasoning/theory building. Researcher starts with interviewing/observing/content analyzing to generate theories for why and how certain social phenomena happen.

Inferential Statistics

Branch of statistics that uses data from a sample to make predictions and conclusions about a larger population.

Inter-Observer Consistency

Measures the level of agreement between researchers observing or assessing the same phenomena.

Internal Reliability

Also referred to as internal consistency. Determines whether multiple measures that are administered in one sitting are consistent. Can be calculated using Cronbach’s alpha coefficient or the split-half method.

Interquartile Range

The distance from the 3rd quartile to the 1st quartile.

Interval-Ratio (Scale)

A level of measurement regarding the distance, or amount of difference between categories. Example

Mean

A measure of central tendency. The average in statistical analysis. Calculated by adding all the values together and then dividing by the total number.

Mean Deviation

A measure of variability that describes the spreading of scores around the mean. Subtract each score from the mean, add the absolute values of all deviations, then divide by the number of cases.

Measurement Validity

Concerned with whether one is measuring what one wants to measure. Different types of measurement validity include face validity, concurrent validity, construct validity, and convergent validity.

Median

A measure of central tendency. The value that is physically in the center of the data when it is arranged in order from lowest to highest.

Mode

The easiest measure of central tendency. The score/value that occurs the most frequently. There can be more than one mode in a data set.

Multi-Stage Cluster Sampling

A type of probability sampling used for large populations. Geographically dispersed groups of elements (clusters) are selected, then subunits within those clusters are selected.

Multivariate

Involving two or more variables.

Nominal

A level of measurement concerned with classifying observations into categories. Categories cannot be ordered or ranked. Example

Non-Probability Sampling

A type of sampling that does not use random selection methods.

Operationalization

The process of converting concepts into indicators or into specific questions in a questionnaire or an interview.

Ordinal

A level of measurement concerned with classifying observations into categories that can be meaningfully ordered in terms of “more or less.” Example

Percentage

Looking at the relation of one part to another part. Frequency (f) divided by the number of cases (n), multiplied by 100.

Percentile

The point below which a specific percentage of cases fall.

Periodicity

The tendency to recur at intervals.

Probability Sampling

A type of sampling that uses random selection methods, associated with quantitative methods.

Range

The most basic measure of variability in data, gives us a sense of how wide a range of data is. (Highest score - Lowest score) + 1.

Rate

The number of actual occurrences of some phenomena, divided by the number of possible occurrences, multiplied by 1000.

Ratio

Compares the relative size of categories- part to part. F1 divided by F2.

Real Limits

Used to construct graphs like histograms. Real limits = states limits + 0.5.

Reliability

Concerned with the consistency of measures. Consists of stability over time, internal consistency/reliability, and inter-observer consistency.

Replication

Provides a check for biases and routine errors. If the findings are not the same as those of the original study, the comparison provides reason to re-evaluate the methods and findings of the original study.

Representative Sample

A sample that is only representative of the population from which it was taken.

Rule of Large Numbers

A math theory within probability that with random sampling, the larger the sample, the more the characteristics of the sample will look like the population as a whole.

Simple Random Sample

A type of probability sampling in which each element has the same probability of being elected. Example

Standard Deviation

A measure of the degree of dispersion of the data from the mean

Statistic

A set of mathematical techniques used by social scientists to organize and manipulate data for the purpose of answering questions and testing theories.

Stratified Random Sampling

A type of probability sampling that subgroups in the population are proportionally represented in the sample.

Systematic Sample

A type of probability sampling in which

Univariate

Analysis of one variable at a time. Frequency tables are typically the first step in this level of analysis.

Variance

How spread out the data is.

Wheel of Science

Summarizes the proper way of conducting a research project according to the basics of GSP.