PSYC stats terms and concepts

50 flashcards covering key concepts from the lecture notes on statistics (data, variables, sampling, data types, levels of measurement, and study designs).

What is statistics?

The range of techniques for analyzing, interpreting, displaying, and making decisions based on data; the language of science and data; adds credibility to arguments.

What is data?

Measured values or pieces of information collected to describe, analyze, or understand phenomena; can be numbers, text, images, or audio.

What is a variable?

A characteristic or feature that can vary between individuals or over time; constants do not change.

Name the three main types of variables.

Independent, dependent, and confounding variables.

What is an independent variable?

The factor deliberately manipulated or observed to determine its effect on another variable; has levels (groups).

What is a dependent variable?

The outcome that is measured or observed and is influenced by the independent variable.

What is a confounding variable?

A variable not of primary interest but may influence other variables.

How do experimental and quasi-experimental designs differ?

Experimental designs involve random assignment and manipulation; quasi-experimental designs lack full random assignment or manipulation.

What is an experimental design?

A design where researchers randomly assign participants to groups and manipulate one or more conditions.

What does level of the independent variable refer to?

The number of groups being compared.

What is a control group?

The group that does not receive the treatment and serves as a baseline for comparison.

What is another name for the independent variable?

Explanatory variable (also called the factor).

What is another name for the dependent variable?

Response variable (also called the outcome).

What does cause and effect mean in experiments?

The independent variable causes changes in the dependent variable; the dependent variable is the effect.

What is population?

The entire group of interest in a statistical study.

What is a sample?

A subset or subgroup drawn from the population.

What is a parameter?

A numerical summary of the population.

What is a statistic?

A numerical summary of a sample (an estimate of a parameter).

Why do we use statistics instead of exact population parameters?

Parameters are often unknown or impractical to measure; statistics allow inference from samples.

In the lake bacteria example, what is the population?

All bacteria species that live in the lake.

In the lake bacteria example, what is the parameter?

The number of species in the lake.

In the lake bacteria example, what is the sample?

The bacteria species that are in the bucket.

In the lake bacteria example, what is the statistic?

The number of species found in the bucket.

What is sampling?

The method of selecting a subgroup from a population.

What is Simple Random Sampling?

Randomly selecting individuals to survey, with each individual having an equal chance of selection.

What is Systematic Sampling?

Selecting individuals based on a rule, such as every nth individual, with a random starting point.

What is Stratified Sampling?

Dividing the population into strata (groups) and sampling from each strata to ensure representation.

What is Cluster Sampling?

Dividing the population into clusters and sampling all individuals within the selected clusters.

What is Convenience Sampling?

Selecting individuals who are easily accessible to the researcher.

What is a stratum?

A subgroup created by dividing the population in stratified sampling.

What is a cluster in cluster sampling?

A group from which all individuals are included in the sample.

What is the purpose of simple random sampling?

To give every individual an equal chance of selection and reduce bias.

What is the purpose of systematic sampling?

To sample using a regular pattern with a random starting point, increasing efficiency while maintaining randomness.

What is the purpose of stratified sampling?

To ensure representation by sampling from each subgroup.

What is the purpose of cluster sampling?

To simplify data collection by studying entire groups rather than individuals.

What is the purpose of convenience sampling?

To conveniently obtain participants when time or access is limited.

What is the difference between population and parameter?

Population is the entire group of interest; a parameter is a numerical summary of that population.

What is the difference between sample and statistic?

A sample is a subset of the population; a statistic is a numerical summary of that sample.

Which levels convey the amount of difference between values?

Interval and Ratio data.

Which level has a true zero point?

Ratio data.

Which levels convey order without specifying magnitude of difference?

Ordinal data.

Which level has categories with no inherent order?

Nominal data.

What are the two main data types?

Quantitative data (numerical) and Qualitative data (categorical).

What is quantitative data?

Data that can be measured numerically.

What is qualitative data?

Categorical data described by categories or verbal descriptions.

What is discrete data?

Countable numbers (integers).

What is continuous data?

Data that may include fractions, decimals, or irrational numbers; measurements.

What is nominal data example?

Gender, color, school (categories without order).

What is ordinal data example?

Ranking or scales such as least to most or disagree to agree.

What is interval data example?

Temperature scales where differences are meaningful but there is no true zero point.

What is ratio data example?

Height, weight, time with a true zero and meaningful ratios.

What is the relationship between population and parameter?

A parameter is a numerical summary of the entire population.

What is the relationship between sample and statistic?

A statistic is a numerical summary of the sample and an estimate of the population parameter.