Section 1.1 | Statistics, Science, and Observations

Question 1

What two general purposes does statistics serve?

Answer 1

1. Satistics are used to organize and summarize the information so that the researcher can see what happened in the research study and can communicate the results to others.
2. Statistics help the researcher to answer the questions that initated the research by determining exactly what general conclusions are justified based on the specific results that were obtained.

Question 2

Define:

statistics

Answer 2

The term statistics refers to a set of mathematical procedures for organizing, summarizing, and interpreting information.

• Statistics helps provide researchers with a set of standardized techniques that are recognized and understood throughout the scientific community.

Question 3

Define:

population

Answer 3

A population is the set of all the individuals of interested in a particular study.

• The population being studied should always be identified by the researcher.
• The population need not consist of people.

Question 4

Define:

sample

Answer 4

A sample is a set of individuals selected from a population, usually intended to represent the population in a research study.

• The goal of the researcher is to generalize the results back to the entire population.

Question 5

Define:

variable

Answer 5

A variable is a characteristic or condition that changes or has different values for different individuals.

Question 6

What is the relationship between data and a data set, and a datum and a score or raw score?

Answer 6

Data (plural) are measurements or observations. A data set is a collection of measurements or observations. A datum (singular) is a single measurement or observation and is commonly called a score or raw score.

• Note that populations and samples are defined in terms of individuals, but these terms can also be applied to scores.

Question 7

Define:

parameter

Answer 7

A parameter is a value, usually a numerical value, that describes a population. A parameter is usually dervied from measurements of the individuals in the population.

Question 8

Define:

statistic

Answer 8

A statistic is a value, usually a numerical value, that describes a sample. A statistic is usually derived from measurements of the individuals in the sample.

• Every population parameter has a corresponding sample statistic, and most research studies involve using statistics from samples as the basis for answering questions about population parameters.

Question 9

Define:

descriptive statistics

Answer 9

Descriptive statistics are statistical procedures used to summarize, organize, and simplify data.

• Used to take raw scores and organize or summarize them in a form that is more manageable.

Question 10

Define:

inferential statistics

Answer 10

Inferential statistics consist of techniques that allow us to study samples and then make generaliztions about the populations from which they were selected.

• One problem with using samples is that it provides only limited information about the population; it’s not expected to give a perfectly accurate picture of the whole population.

Question 11

Define:

sampling error

Answer 11

Sampling error is the naturally occurring discrepancy, or error, that exists between a sample statistic and the corresponding population parameter.

• Sampling errors can arise as a result of natural differences between people, unproportional representation, or just pure chance.