30 terms

Data

consist from information coming from observations, counts, measurements, or responses

Statistics

the science of collecting, organizing, analyzing, and interpreting data in order to make decisions

Population

the collection of all outcomes, responses, measurements, or counts that are of interest

Sample

a subset, or part, of a population

Parameter

a numerical description of a population characteristic

Statistic

a numerical description of a sample characteristic

Descriptive statistics

the branch of statistics that involves the organization, summarization, and display of data

Inferential statistics

the branch of statistics that involves using a sample to draw conclusions about a population; a basic tool used is probability

Qualitative data

consist of attributes, labels, and nonnumerical entries

Quantitative data

consist of numerical measurements or counts

Nominal level of measurement

are qualitative only and are categorized using names, labels, or qualities; no mathematical computations can be made

Ordinal level of measurement

are qualitative or quantitative and can be arranged in order, or ranked, but differences between data entries are not meaningful

Interval level of measurement

can be ordered, and meaningful differences between data entries can be calculated; a zero entry simply represents a position on a scale; the entry is not an inherent zero

Ratio level of measurement

similar to data at the interval level, with the added property that a zero entry is an inherent zero; a ratio of two data entries can be formed so that one data entry can be meaningfully expressed as a multiple of another

Observational study

a researcher does not influence the responses

Experiment

a researcher deliberately applies a treatment before observing the responses

Treatment

applied to a group called the treatment group

Control group

receives no treatment

Placebo

a harmless, fake treatment that is made to look like the real treatment

Simulation

the use of a mathematical or physical model to reproduce the conditions of a situation or process

Survey

an investigation of one or more characteristics of a population

Confounding variable

occurs when an experimenter cannot tell the difference between the effects of different factors on the variable

Blinding

a technique where the subjects do not know whether they are receiving a treatment or a placebo

Double

blind experiment- neither the experimenter nor the subjects know if the subjects are receiving a treatment or a placebo

Randomization

a process of randomly assigning subjects to different treatment groups

Sample size

the number of subjects in a study

Replication

the repetition of an experiment under the same or similar conditions

Census

a count or measure of an entire population

Sampling

a count or measure of part of a population

Convenience sample

leads to biased studies