Introduction to Statistics

Summarizes and presents data to make it easier to analyze and interpret. Includes tables, graphs, and measures of central tendency and variability.

Draws conclusions about a population based on a sample.

The complete set of all elements to be studied.

A subgroup of a population, used for studying the population.

A variable with non-numerical values/categories. Examples: Colors, types of cars.

A variable with numerical values (e.g., height, weight).

Values assumed by variables; characteristics used to distinguish different elements in a population or sample.

Methods for planning, collecting, organizing, summarizing, analyzing, interpreting, and drawing conclusions from data.

Different types of variables, defining how they are analyzed (nominal, ordinal, interval, ratio).

Variables that only consist of names, labels, or categories.

Data that can be ordered, but the differences between values are meaningless.

Data with meaningful differences between values, but no inherent zero point.

Interval variables with an inherent zero point, allowing meaningful ratios between values.

A probability sampling method where each member has an equal chance of selection.

Techniques used by researchers to gather information for their studies. They can be interviews, questionnaires, observation, experiments, or digital methods like texting.

A direct, personal conversation between the researcher and a participant to obtain information.

Distributing surveys or questionnaires to a group of people to collect data and identify patterns.

Gathering data using officially recorded information from sources like government agencies.

A scientific process designed to test the cause and effect relationship between variables under controlled conditions.

Watching and recording the behavior of individuals or groups to gather data and insights.

Collecting data via text messages, emails, or online forms to gather opinions and feedback.

Organizing data into tables, graphs, or charts for better understanding and analysis.

Selecting participants based on an expert's judgment, focusing on individuals with specific traits or experiences.

Choosing participants who are readily available or easy to access, aiming for quick and accessible data.

Dividing the population into subgroups based on specific characteristics and selecting participants from each subgroup to meet predetermined numbers (quotas).

Using participants to refer other potential participants with similar traits, especially useful for rare characteristics or hard-to-reach populations.

Purposive sampling involves expert judgment to select participants based on specific traits, while convenience sampling chooses readily available participants.

To ensure representation of different subgroups within the sample, reflecting the characteristics of the population.

It relies on referrals from existing participants to reach individuals with specific traits, especially helpful when participants are hard to find directly.

Snowball sampling targets specific traits through referrals, while convenience sampling focuses on readily available individuals.

The mean might not accurately represent the average value because extreme values can pull the mean towards them.

The difference between the highest and lowest values in a dataset.

Measures how spread out the data is from the mean. It uses the deviation of each value from the mean.

Measures the strength and direction of the relationship between two variables.

A number between -1 and +1 that indicates the strength and direction of a correlation.

Used to predict one variable by another, assuming a straight line relationship.

A visual representation of points (vertices) connected by lines (edges).

All vertices can be reached from any other vertex by following edges.

A connected graph where every vertex has an edge to every other vertex, with no repeated edges.

A circuit that traverses every edge of a graph exactly once and ends at the starting vertex.

A connected graph has an Euler circuit if and only if every vertex has an even degree.

A circuit in a graph that visits every vertex exactly once.

A graph that can be drawn without any edges crossing each other (except at vertices).