Research Flashcards
case studies
descriptive records of one or more individual’s experiences and behavior.
survey—
a measure administered through either an interview or a written questionnaire to get a picture of the beliefs or behaviors of a sample of people of interest. The people chosen to participate in the research (known as the sample) are selected to be representative of all the people that the researcher wishes to know about (the population).
naturalistic observation—
is research based on the observation of everyday events.
descriptive statistics—
numbers that summarize the distribution of scores on a measured variable.
arithmetic mean,
is the most commonly used measure of central tendency. It is computed by calculating the sum of all the scores of the variable and dividing this sum by the number of participants in the distribution
Dispersion
refers to the extent to which the scores are all tightly clustered around the central tendency,
positive linear
When the straight line indicates that individuals who have above-average values for one variable also tend to have above-average values for the other variable
Negative linear relationships
, in contrast, as shown in part (b), occur when above-average values for one variable tend to be associated with below-average values for the other variable.
curvilinear relationships.
Relationships that change in direction and thus are not described by a single straight line
Pearson correlation coefficient,
which is symbolized by the letter r. The value of the correlation coefficient ranges from r= –1.00 to r = +1.00.
The direction of the linear relationship is indicated by the sign of the correlation coefficient. Positive values of r indicate that the relationship is positive linear whereas negative values of r (r = –.72) indicate negative linear relationships. The strength of the linear relationship is indexed by the distance of the correlation coefficient from zero
Multiple regression
is a statistical technique, based on correlation coefficients among variables, that allows predicting a single outcome variable from more than one predictor variable.
common-causal variable/ third variable
is a variable that is not part of the research hypothesis but that causes both the predictor and the outcome variable and thus produces the observed correlation between them
A spurious relationship
is a relationship between two variables in which a common-causal variable produces and “ explains away‖ the relationship
The independent variable in an experiment
is the causing variable that is created (manipulated) by the experimenter
The dependent variable in an experiment
is a measured variable that is expected to be influenced by the experimental manipulation
random assignment to conditions,
a procedure in which the condition that each participant is assigned to is determined through a random process, such as drawing numbers out of an envelope or using a random number table.
confounding variables
—variables other than the independent variable on which the participants in one experimental condition differ systematically from those in other conditions.
experimenter bias,
a situation in which the experimenter subtly treats the research participants in the various experimental conditions differently, resulting in an invalid confirmation of the research hypothesis.
blind to condition.
This means that although the experimenters know the research hypotheses, they do not know which conditions the participants are assigned to.
double-blind experiment,
both the researcher and the research participants are blind to condition