Variables
The variable whose values are chosen or manipulated by the researcher.
What is the independent variable?
In this design, a researcher does not directly manipulate the IV. For example, seeing the effects of gender on emotional expression.
What is a quasi-experimental design?
A scale comprising items that ask for ratings, often with 7 points, of a respondent’s strength of agreement or disagreement with a number of statements.
What is a Likert Scale?
A statement about the population that we wish to test and states that there has been no change, or that an effect is zero.
What is a null hypothesis?
A usually very large set of people about which we are interested in drawing conclusions.
What is a population?
The condition that provides a baseline or starting point for a comparison
What is the control condition?
In this design, each participant is tested on only one of conditions being compared.
What is a between subjects design?
A measure of the strength of association between two variables, such as Pretest and Posttest; It can take values from −1 through 0 to 1.
What is r, or a correlation?
This is the probability of obtaining the observed result or more extreme, IF the null hypothesis is true.
What is a p value?
This distribution is more complex than the z distribution—it depends on the degrees of freedom.
What is the t distribution?
The different values taken by the independent variable. Also called conditions or treatments.
What are levels?
Uses random assignment of participants to groups or conditions—to the different levels of the IV that is being manipulated. It is used to justify a causal conclusion
What is an experiment/ experimental design?
A pictorial representation of the relation between X and Y, in which each data pair is represented by a dot.
What is a scatterplot?
This type of test includes values that differ in one direction from the null hypothesis value. For example, H1: m > 50.
What is a directional/one tailed test?
This theorem states that the sum, or the mean, of a number of independent variables has, approximately, a normal distribution, almost whatever the distributions of those variables.
What is the central limit theorem?
An unwanted difference between groups, which is likely to limit the conclusions we can draw from a study.
What is a confound/ confounding variable?
In this design, all levels of the variable are seen by a single groups of participants.
What is within subjects/ repeated measures?
A measurement is said to have a high amount of this when the measurement is consistent.
What is reliability?
This is a false positive, or the rejection of H0 when it’s true.
What is Type 1 Error?
The standard deviation of the sampling distribution of the sample mean
What is the standard error?
A variable that can take any of the unlimited number of values in some range
What is a continuous variable?
The assignment of different participants to different orders of presentation, or different versions of the same condition, to reduce carryover effects.
What is counterbalancing?
Independent variables in t and F tests must be this type of variable/ level measurement.
What is categorical/nominal?
This test uses a p value to test the null hypothesis of zero difference between two means in a between subjects study.
What is an independent samples t-test?
A smooth curve that plots probability density against X. Areas under the curve represent probability, and the total area under the curve is 1.
What is a probability distribution/ probability density function?