2.2.3 and 2.2.4 Flashcards
Correlation coefficient
A statistical index of the relationship between two things (from -1 to +1)
Scatter plot
A graphed cluster of dots each of which represents the values of two variables. The slope of the points suggest the direction of the relationship between the two variables. The amount of scatter suggests the strength of the correlation (little scatter indicates high correlation)
Saying that a correlation is “negative” does not say anything about….
It’s strength or weakness
A correlation is negative when…
One goes up and one goes down
Statistics can help us see…
What the naked eye sometimes misses
Correlations can help us
Predict
No matter how strong a relationship….
it does not prove anything
Illusory correlation
The perception of a relationship where none exists
When we see a random coincidences…
we may forget that they are random and instead see them as a correlation
Something random can be seen as…
In order
Experiment
A research method in which an investigator manipulates one or more factors (independent variables) to observe the effect on some behavior or mental process (the dependent variable) be random assignment of participants the experimenter aims of control other relevant factors
Experiments enable a researcher to focus on the possible effects of one or more factors by
Manipulating the factors of interest and holding consent (controlling) other factors
Random assignment
Assigning participants to experimental and control groups by chance this minimizing preexisting differences between those assigned to the different groups
Correlational=
Natural
Experiment
Manupulative
Double-blind procedure
An experimental procedure in which both the research participants and the research staff are ignorant about whether the research participants have received the treatment or a placebo. Commonly used in the drug-evaluation studies
Placebo effect
Experimental results caused by the expectant films along; and effect on behavior caused by the administration of an inert substance or condition which the recipient assumes is an active agent
Experimental group
In an experiment the group that is exposed to the treatment that is to one version of the independent variable
Control group
In an experiment the group that is not exposed to the treatment; contrast with the experimental group and serves as a comparison for evaluating the effect of the treatment
Independent variable
The experimental facto that is manipulated
Confounding variable
A factor other than the independent carnival that might produce and effect in an experiment
Dependent variable
The outcome factor; the variable that may change in response to manipulations of the independent variable
Correlation
A measure of the extent to which who factors vary together and thus of how well either factor predicts the other
