CHAPTER 2: RESEARCH VARIABLES

A set of vocabulary flashcards covering research variables, measurement levels, sampling techniques, and various types of research designs.

Variable

Any characteristic, number, or quantity that can be measured or counted; also factors that can be manipulated and measured in a scientific experiment.

Measurement

The process of determining the value or label of a particular variable for a particular individual or object.

Discrete Variable

A variable that can assume a finite or at most, countable infinite number of values, usually measured by counting or enumeration with no fractional or decimal values between two points.

Continuous Variable

Also known as non-discrete variables, these cannot be counted because of their distinct division and can assume values corresponding to a line of interval.

Qualitative Variable

A variable that can give categorical responses, such as occupation, gender, civil status, or religious affiliation.

Quantitative Variable

A variable that takes on numerical values representing an amount or quantity, such as height, salary, weight, or time.

Independent Variable

Variables that the researcher controls or manipulates in accordance with the purpose of the investigation.

Dependent Variable

Variables that are measured based on the effect of the independent variables, sometimes called an outcome variable.

Univariable Distribution

A distribution where there is only one variable involved, such as the age of grade 7 pupils.

Bivariable Distribution

Data that are classified on the basis of two variables, such as ice cream sales versus the temperature of the day.

Multivariable Distribution

Data where each datum belongs to three or more variables, such as enrollment in terms of program, year level, and gender.

Nominal Scale

A scale that has no numerical value and is sometimes called a categorical scale or categorical data.

Ordinal Scale

A scale that classifies subjects and ranks them in order from highest to lowest or most to least based on the degree to which they possess a characteristic.

Interval Scale

A scale based upon predetermined equal intervals that consists of real numbers but does not have a true zero point, using arbitrary maximum or minimum scores.

Ratio Scale

The highest and most precise level of measurement which has a meaningful true zero point where none of the quality being measured exists.

Population

The total or entire group of individuals, events, or objects from which information is desired; sometimes referred to as the universe.

Sample

A portion or subset of the population that truly represents the unique qualities or characteristics of the entire group.

Slovin's Sampling Formula

$\text{n} = \frac{N}{1 + Ne^2}$ where $n$ is sample size, $N$ is population, and $e$ is the estimated margin of error.

Probability Sampling

A sampling technique in which every member of a population has a known, non-zero chance of being selected, involving random selection to reduce bias.

Simple Random Sampling

A probability sampling type where every individual has an equal chance of being selected, such as drawing names from a hat.

Systematic Sampling

A probability sampling type involving the selection of every k-th individual from a list.

Stratified Sampling

A probability sampling type where the population is divided into subgroups (strata) and samples are randomly selected from each group to ensure representation.

Cluster Sampling

A probability sampling type where the population is divided into clusters (often geographically) and entire clusters are randomly selected.

Non-probability Sampling

A sampling technique where not all members of the population have a known or equal chance of being selected, often using subjective selection.

Convenience Sampling

A non-probability sampling type where individuals who are easiest to reach are chosen.

Judgmental or Purposive Sampling

A non-probability sampling type where selection is based on the researcher's knowledge and judgment.

Snowball Sampling

A non-probability sampling type where existing participants recruit future subjects from among their acquaintances.

Quota Sampling

A non-probability sampling type where the population is segmented into groups and a specific number of participants are selected non-randomly from each group.

Voluntary Sampling

A non-probability sampling type where individuals volunteer themselves to be part of the sample.

Research Design

The overall strategy or blueprint used to integrate different components of a research study in a coherent and logical way; a structured plan for collecting, measuring, and analyzing data.

Exploratory Research

Research conducted to clarify ambiguous problems or gain a better understanding of an issue when there are few earlier studies to refer to.

Descriptive Research

A research method focused on describing the characteristics of a population, phenomenon, or situation without answering why things happen.

Explanatory Research

Also known as causal research, this is conducted to understand the cause-and-effect relationships between variables and explain why things happen.

Action Research

A systematic process of inquiry conducted by practitioners to improve their own practices, solve problems, or make decisions in real-time contexts.

Correlational Research

A non-experimental research method used to measure and assess the relationship between two or more variables without manipulating them.

Evaluation Research

A systematic investigation that assesses the design, implementation, and outcomes of programs, policies, or projects to determine effectiveness and efficiency.

Ex-Post Facto Research

A type of non-experimental research that seeks to identify possible causes for existing differences in groups by studying variables after they have occurred.

Historical Research

The systematic study of past events, people, and societies through the collection and interpretation of evidence like documents and artifacts.

Ethnographic Research

A qualitative research method focused on immersive observation and participation to understand the social behaviors and beliefs of a group in their natural environment.

Phenomenological Research

A qualitative research approach focused on exploring and understanding individuals' lived experiences and the meanings they attach to them.