Sampling Methods and Descriptive Statistics in Research

What distinguishes non-random sampling from random sampling?

In non-random sampling, not everyone in the population has an equal probability of inclusion.

What is a purposive sample?

A sample selected based on unique characteristics present in the population of interest.

How does a quota sample function?

Inclusion is based on known proportions of the population.

What is a convenience sample?

A sample based on the availability of participants.

What is a network sample?

A sampling method where one participant is recruited and asked to refer others.

What is a multi-stage cluster sample?

A large-scale sampling method where sampling occurs at different levels.

What is a simple random sample?

A method where everyone in the population has an equal chance of inclusion, such as drawing names from a hat.

How is a systematic sample with a random start conducted?

The population is sampled at fixed intervals (e.g., every 50th person) starting from a randomly selected number.

How does a stratified sample work?

The population is divided into groups based on known parameters, and a set number of participants is selected from each.

What is a proportional stratified sample with a random start?

A combination of systematic and stratified sampling that selects participants in proportion to their representation in the population.

What is the difference between descriptive and inferential statistics?

Descriptive statistics describe properties of a dataset; inferential statistics estimate parameters of a population.

What are the three measures of central tendency?

Mean, median, and mode.

Which measure of central tendency is resistant to outliers?

Median (non-parametric).

What does a negative skew indicate?

The data is skewed left, meaning the outlier is on the left.

What does a positive skew indicate?

The data is skewed right, meaning the outlier is on the right.

What are the four measures of dispersion?

Range, interquartile range, standard deviation, and variance.

How is range defined?

The distance between the lowest and highest scores in a distribution.

What is the standard deviation?

A measure of how many units a data point is away from the center of the dataset.

What is considered an outlier in relation to standard deviation?

Any value that is plus or minus standard deviations from the mean.

What is the difference between conceptualization and operationalization?

Conceptualization is the dictionary definition; operationalization is how you measure that concept.

What is triangulation in research?

Using test/retest methods to ensure consistency on the dependent variable.