Ch 1 Flashcards
Population & Samples
Population-whole group (the set of all the individuals of interest in a particular study, characteristics are parameters PP)
Samples-small representative group (set of individuals must be selected from the population, characteristics are statistics SS)
Variables
measurable or recordable characteristic/condition that changes or has different value/level for different individuals (ex: age, gender, temp of room)(ways to describe: independent, dependent, extraneous, confounding, quasi-independant)
Data/ Datum
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.
Parameters & Statistics
A parameter is a value, usually numerical, that describes a population usually derived from measurements of the individuals in the population.
A statistic is a value, usually numerical value, that describes a sample usually derived from measurements of the individuals in the sample
Descriptive Statistics
Statistical procedures used to summarize, organize, and
simplify data.
-only about sample data (%, range, standard dev)
Sampling Error
the naturally occurring discrepancy, or error, that exists between
a sample statistic and the corresponding population parameter
Inferential statistics
consist of techniques that allow us to study samples and then
make generalizations about the populations from which they were selected.
-use sample to apply to population
(z- and t- scores)
Correlational Method
two different variables are observed to determine
whether there is a relationship between them.
-unlike experimental, cannot demonstrate cause and effect
correlation
- measured natural relationship between two variables (moving up and down together- must be more or less variables not variables like gender)
- AS THEY ARE does NOT establish cause and effect
- does not easily explain relationship
experimental method
goal of an experimental
study is to demonstrate a cause-and-effect relationship between two variables (using 1-manipulation and 2-control of extraneous variables)
experimental method
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.
Independent Variable (cause)
the variable that is manipulated by the researcher. In
behavioral research, the independent variable usually consists of the two (or more) treatment conditions to which subjects are exposed. The independent variable consists of the
antecedent conditions that were manipulated prior to observing the dependent variable.
-we can change it independently of the DV
Dependent Variable (effect)
one that is observed to assess the effect of the treatment.
- the variable we measure
- this variable is dependent on our IV
Random assignment
-each participant has an equal
chance of being assigned to each of the treatment conditions.-equalizes extraneous variables by ensuring extraneous variables do not vary systematically…. they will vary unsystematically in an unbiased sample
extraneous variables should be controlled (control variables)
participant variables, environmental variables, okay as long as they do not vary systematically across groups which would be confounding variables