Gravetter chp 1+2 Terminologi Flashcards
Statistics
A set of mathematical procedures for organizing, summarizing, and and interpreting information.
Population
Characteristic of all the individuals of interest in a particular study.
Sample
A set of individuals selected from a population, usually intended to represent the population in a research study.
Variable
A characteristic or condition that changes or has different values for different individuals. Fx depressionsscore for alle børn af forældre med alkoholproblemer.
Data set
Collection of measurements of observations.
Datum (sing)
A single measurement or observation, is commonly called a score or raw score.
Parameter
A value, usually numeric, that describes a population. Usually derived from measurements of the individuals in the population.
Statistic (sing)
A value, usually numeric, that describes a sample. Usually derived from measurements of the individuals in the population.
Descriptive statistics
Statistical procedures used to summarize, organize, and simplify data.
Inferential statistics
Consists of techniques that allow us to study samples and then make generalizations about the populations from which they were selected.
Sampling error
The naturally occurring discrepancy, or error, that exists between a sample statistic and the corresponding population parameter.
Correlational method
Two different variables are observed to determine whether there is a relationship between them.
Experimental method
One variable is manipulated while another is observed and measured. To establish a cause-and-effect relationship between the two variables, an experiment attempts to control all other variables to prevent them from influencing the results.
Independent variable
The one that is manipulated. Usually consists of two or more treatment conditions to which subjects are exposed. It consists of the antecedent conditions that were manipulated prior to observing the dependent variable.
Dependent variable
The one that is observed.
Control condition
Individuals in this condition do not receive the experimental treatment. Provides a baseline for comparison.
Experimental condition
Here, the individuals receive the experimental treatment.
Quasi-independent variable
In a nonexperimental study, this is the variable used to create the different groups of scores.
Constructs
Internal attributes or characteristics that cannot be directly observed but are useful for describing and explaining behavior.
Operational definition
Identifies a measurement procedure for measuring an external behavior and uses the resulting measurements as a definition and a measurement of a hypothetical construct. It has two components; first, it describes a set of operations for measuring a construct. Secondly, it defines the construct in terms of the resulting measurements.
Discrete variable
Consists of separate, indivisible categories. No values can exist between two neighbouring categories.
Continuous variable
There are an infinite number of possible values that fall between any two observed values. A continuous variable is divisible into an infinite number of fractional parts.
Real limits
The boundaries of intervals for scores that are represented on a continuous number line. The real limit separating two adjacent scores is located exactly halfway between the scores. Each score has two real limits. Upper and lower real limit.
Nominal scale
Consists of a set of categories that have different names. Measurements on a nominal scale label and categorize observations, but do not make any quantitative distinctions between objects.
