Statistics 2300 Chapter 1.1 Review

Statistics

The science of collecting, organizing, summarizing, and analyzing data to answer questions.

Lurking Variables

Hidden factors that may influence the relationship between the variables being studied, potentially leading to misleading conclusions.

Anecdotal Claims

Statements based on personal accounts or isolated examples rather than systematic evidence or statistical analysis. They can often be misleading and do not provide a reliable basis for conclusions.

Individuals

The subjects or objects from which data are collected in a study, such as people, animals, or items.

Population

The entire group of individuals that is being studied.

Sample

A subset of the population that we actually collect data from.

Parameter

A numerical summary of the population.

Statistic

A numerical study of a sample.

Descriptive Statistics

Methods for summarizing the collected data, this can be done through tables, graph, and numerical summaries such as averages or percentages.

Inferential Statistics

Methods that take a result from a sample, extend it to the population, and measure the reliability of the result.

The Process of Statistics

1. Identify the research objective

2. Collect the data needed to answer the question posed

3. Describe the data

4. Perform the inference

Variable

Any characteristics of the individual within the population.

Quantitative Variable

Observations on it take numerical values that represent different magnitudes of the variable.

Qualitative (Categorical) Variable

If each observation belongs to one of a set of categories.

Nominal Level

A variable is at the nominal level of measurement if the values of the variable name, label, or categorize. (Qualitative)

Ordinal Level

A variable is at the ordinal level of measurement if it has the properties of the nominal level of measuremnet, but the naming scheme allows for the values to be ranked or ordered. (Qualitative)

Interval Level

A variable is at the interval level of measurement if it has the properties of the ordinal level of measurement, but the difference in the values of the variables have meaning, values can be meaningfully added or subtracted. (Quantitative)

Ratio Level

A variable is at the ration level of measurement if it has the properties of the interval level of measurement, but the ratios of the values of the variables have meaning, values can be meaningfully multiplied or divided. (Quantitative)