Practical Research Lessons 1-3

Research

is a systematic and logical process of collecting and analyzing information to increase our understanding of a topic or problem.

Basic Research

A type of research that aims to expand general knowledge.

Example: Understanding how memory works

Applied Research

A type of research that aims to solve specific problems.

Example: Testing which study technique helps students improve scores

Quantitative Research

A systematic investigation that collects and analyzes numerical data to describe, explain, predict, or control variables of interest. It is objective, measurable, and often used to test hypotheses. Includes numbers and statistics. Large sample size.

Examples: How many hours do students study per day?

Qualitative Research

A type of research wherein data explores meaning, includes opinions and interviews. Small sample size.

Example: Why do some students prefer group work?

Descriptive Research

A kind of research design

Purpose: To provide a description of the characteristics of a population or phenomenon.

Example: A survey that determines the average age of university students in a country.

Methods: Surveys, observations, and existing data analysis.

Key Feature: It answers “what is” but not “why” or “how.”

Correlational Research

A kind of research design

Purpose: To determine the correlation between two or more variables.

Example: Studying the correlation between screen time and academic performance.

Methods: Surveys and observational data.

Key Feature: No manipulation of variables; does not establish causation.

Experimental Research

A kind of research design

Purpose: To determine cause-and-effect relationships by manipulating one variable and observing changes in another.

Example: Testing the effectiveness of a new teaching method on student performance.

Methods: Controlled experiments with random assignment to groups.

Key Feature: Involves independent and dependent variables, control groups, and randomization.

Quasi-Experimental Research

A kind of research design

Purpose: To explore cause-and-effect relationships when random assignment is not feasible.

Example: Comparing the academic performance of students in two different schools using different curricula.

Methods: Similar to experimental research but without random assignment.

Key Feature: Useful in real-world settings, but with limited control over variables.

Longitudinal Research

A kind of research design

Purpose: To study variables over a long period.

Example: Tracking changes in health behavior over 10 years.

Methods: Repeated observations or surveys at multiple time points.

Key Feature: Helps identify trends and long-term effects.

Cross-Sectional Research

A kind of research design

Purpose: To examine data from a population at a particular moment in time.

Example: Taking a one-month survey of people's views on climate change.

Methods: Surveys, assessments, observational data.

Key Feature: Quick snapshot; cannot assess changes over time

Causal-Comparative Research (Ex Post Facto)

A kind of research design

Purpose: To compare two or more groups to find out if there are significant differences between them based on a specific variable — but without manipulating any variables.

Example: Do male and female students differ in their science achievement scores?

Methods: Surveys, tests, or checklists to gather data. Measure the dependent variable

Key Feature: Groups are pre-existing, no manipulation, study happens “after the fact”

Independent Variable (IV)

The variable that is manipulated or changed by the researcher to see its effect on the dependent variable.

Example: Amount of sleep (4 hrs, 6 hrs, 8 hrs)

Dependent Variable (DV)

The variable that is measured or observed. It changes depending on the IV; it’s the result/output.

Example: Quiz scores based on sleep amount

Controlled Variable

A variable that is kept the same to ensure a fair test. To ensure that only the IV affects the DV.

Example: Same classroom, same test, same teacher

Extraneous Variable

A variable that is not intentionally studied but may still affect the DV.

May introduce error or bias if not controlled.

Example: Student’s mood, prior knowledge, health.

Moderator Variable

A variable that affects the strength or direction of the relationship between the IV and DV.

It answers questions about when, for whom, or under what conditions an effect occurs.

Example: Daytime and nighttime may moderate the effect of brightness of a light in a room.

Mediating Variable (or Intervening)

A variable that explains the connection between IV and DV. Acts as a bridge in the cause-effect chain.

Example: Motivation may mediate the link between study time and grades

Confounding Variable

An outside, unmeasured factor influences both the independent and dependent variables, creating a false or unclear relationship between them.