GEA1000 Week 2 Variables

What is a Variable?

An attribute that can be measured or labelled

What is a data set?

Consists of individuals and variables pertaining to the individuals

What is an independent variable?

A variable that may be subject to manipulation (either deliberately or spontaneously) in a study.

What is an dependent variable?

A variable which is hypothesized to change depending on how the independent variable is manipulated in a study.

Types of Variables

1) Categorical Variables

2) Numerical Variables

Categorical Variables

A data type that sorts information into distinct groups, labels, or categories.

E.g., eye colour, maritial status

Numerical Variables

A data type expressed in numbers that represents a measurable quantity or count.

E.g., height, weight, temperature, money, distance

Types of Categorical Variables

1) Ordinal Variables
2) Nominal Variables

Ordinal Variables

A specific type of categorical variable where the categories have a natural, logical order or ranking.

Nominal Variables

A type of categorical variable used to name, label, or classify data into distinct groups without any quantitative value or inherent order.

Warnings for Ordinal Data

Calculating averages (the mean) for ordinal data is a major statistical trap that can lead to deeply misleading conclusions.

Types of Numerical Variables

1) Discrete Variables

2) Continuous Variables

Discrete Variables

A type of numerical variable that can only take on specific, isolated values—usually whole numbers—that you can obtain by counting

Continuous Variables

A type of numerical variable that can take on an infinite number of possible values within a given range

Experimental Studies

A research method where the researcher actively manipulates one or more independent variables to observe their effect on a dependent variable

Treatment Group

The specific group of participants in a study who receive the actual intervention, therapy, or condition being tested.

Control Group

The group of participants in an experiment who do not receive the active treatment or intervention being tested

Reason for control group

Control Group provides a baseline for comparison with the treatment group.

Random Assignment

The process of using chance to sort experimental participants into different groups.

If the number of subjects is large, by the laws of probability, the treatment and control groups will tend to be similar in all aspects.

What is a Placebo

A dummy or inactive substance, treatment, or procedure that has no physical or medical power to cure an illness, but is designed to look, feel, and taste exactly like a real medical treatment.

Placebo Effect

The response observed when subjects receive a placebo treatment, but still show some positive effects.

Blinding

A research technique where information about who is receiving the active treatment and who is receiving the placebo is withheld from the people involved in the study

Blinding Assessors

For the prevention of biasedness as assessors do not know whether they are assessing the treatment or control group.

Ethical Issues

The moral principles and rules that protect participants from harm and ensure a study is conducted honestly. Because experiments involve manipulating human behavior, environments, or bodies, strict ethical guidelines must be followed.

Observational Studies

A research method where the researcher simply observes and measures subjects without manipulating any variables or intervening in the environment.

Types of Observational Studies

1) Cohort Studies

2) Case-Control Studies

Cohort Studies

A specific type of observational study where researchers track a group of people (called a cohort) over time to see how different exposures or behaviors affect their future outcomes.

Case-Control Studies

A type of observational study that works backward in time, starting with the final outcome or disease to figure out what might have caused it