Chapter 1 Flashcards
a set of mathematical procedures for organizing, summarizing, and interpreting information
statistics
the set of all the individuals of interest in a particular study
population
a set of individuals selected from a population, usually intended to represent the population in a research study
sample
a characteristic or condition that changes or has different values for different individuals
variable
measurements or observations
data (plural)
a collection of measurements or observations
data set
a single measurement or observation and is commonly called a score or raw score
datum (singular)
is a value, usually a numerical value, that describes a population, is usually derived from measurements of the individuals in the population
parameter
a value, usually a numerical value, that describes a sample, usually derived from measurements of the individuals in the sample
a statistic
statistical procedures used to summarize, organize, and simplify data
descriptive statistics
consist of techniques that allow us to study samples and then make generalizations about the populations from which they were selected
inferential statistics
the naturally occurring discrepancy, or error, that exists between a sample statistic and the corresponding population parameter
sampling error
two different variables are observed to determine whether there is a relationship between them
the correlational method
the researcher manipulates one variable by changing its value from one level to another
manipulation
the researcher must exercise control over the research situation to ensure that other, extraneous variables do not influence the relationship being examined
control
characteristics such as age, gender, and intelligence that vary from one individual to another
participant variables
characteristics of the environment such as lighting, time of day, and weather conditions
environmental variables
one variable is manipulated while another variable 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
the experimental method
the variable that is manipulated by the researcher; in behavioral research, it usually consists of the two (or more) treatment conditions to which subjects are exposed and the antecedent conditions that were manipulated prior to observing the dependent variable
independent variable
the variable that is observed to assess the effect of the treatment
dependent variable
individuals do not receive the experimental treatment; instead, they either receive no treatment or they receive a neutral, placebo treatment — the purpose of this is to provide a baseline for comparison with the experimental condition
control condition
individuals in this condition do receive the experimental treatment
experimental condition
in a nonexperimental study, the “independent variable” that is used to create the different groups of scores
quasi-independent variable
the relationship between the two variables is usually measured and described using a statistic called a…
correlation
What two elements are necessary for a research study to be an experiment?
- the researcher must manipulate one of the two variables being studied
- all other variables that might influence the results must be controlled
internal attributes or characteristics that cannot be directly observed but are useful for describing and explaining behavior
constructs
identifies a measurement procedure (a set of operations) for measuring an external behavior and uses the resulting measurements as a definition and a measurement of a hypothetical construct
operational definition
What are the two components of an operational definition?
- it describes a set of operations for measuring a construct
- it defines the construct in terms of the resulting measurements
consists of separate, indivisible categories — no values can exist between two neighboring categories
discrete variable
there are an infinite number of possible values that fall between any two observed values; is divisible into an infinite number of fractional parts
continuous variable
the boundaries of intervals for scores that are represented on a continuous number line; located exactly halfway between the scores
real limits
Each score has two real limits. The upper real limit is at the top of the interval, and the lower real limit is at the bottom.
consists of a set of categories that have different names; measurements label and categorize observations, but do not make any quantitative distinctions between observations
nominal scale
consists of a set of categories that are organized in an ordered sequence; rank observations in terms of size or magnitude
ordinal scale
consists of ordered categories that are all intervals of exactly the same size. Equal differences between numbers on a scale reflect equal differences in magnitude. However, the zero point on an interval scale is arbitrary and does not indicate a zero amount of the variable being measured.
interval scale
an interval scale with the additional feature of an absolute zero point; ratios of numbers do reflect ratios of magnitude
ratio scale
When measuring height to the nearest inch, what are the real limits for a score of 68 inches?
67.5 and 68.5
When measuring height to the nearest half inch, what are the real limits for a score of 68 inches?
67.75 and 68.25
is used to specify how many scores are in a set
N
upper case N
number of scores in a population
lower case N
number of scores in a sample
ΣX
sum of the scores
variables like intelligence, anxiety, and hunger
constructs (or hypothetical constructs)
