Flashcards in Chapter 10 Practice Questions Deck (21)
What is systematic between group variance?
Systematic between groups variance reflects consistient group differences due to independent variable, uncontrolled confounding variable or both.
Define experimental variance
Experimental variance is due to the effect of the independent variable.
What is error variance?
Error variance is the nonsystematic within groups variability that is due to random factors that affect some participants more than others or to individual differences.
What is f test?
The F test is an inferential statistical procedure.
What is f test used for?
The f test tests for group differences.
What are the ways of controlling extraneous variance?
They are controlled by making sure that the experimental and the controlled groups are as similar as possible and treating all the same way except for the independent variable manipulation.
Define extravenous variable?
Extraneous variance is due to the effects of uncontrolled confounding variables.
How can error variance be minimized?
It can be minimised through careful measurement and/or using a correlated groups design to control individual differences.
Of these four non experiemental what is the weakest and why?
The weakest design is the ex post factor design which controls virtually none of the potential confounding variable.
When is maturation not considered a confounding variable?
Maturation is not considered a confounding variable in studies of development.
What type of design do researchers use to study maturational processes?
Development studies typically employ time series designs.
What is the most basic experimental design?
Randomised, post test only control group design.
What do control groups control for?
History, maturation and regression to the mean.
Control groups are effective only if...
Participants are randomly assigned to groups to assure that the groups are comparable at the beginning of the study and they are treated exactly the same during the study except for the independent variable manipulation.
What does the Solmon four group design control for?
The Solmon four group design controls for the possible interaction of the pretest and treatment.
What could happen if groups are not equivalent at the beginning of the study?
Observed differences could be due to the manipulation, the initial differences, or both.
When is ANOVA used?
ANOVA is used when two or more groups are compared on a dependent measure that produces score data.
What does the ANOVA summary table show ?
The ANOVA summary table shows the sources of variance, the degree of freedom for each source of variance, the sum of squares, the mean squares, the F ratios and the probability values for each F.
Why is the f ratio significant?
When at least one mean is significantly different from at least one other mean.
Would it be unethical for researchers to randomly assign participants that expose them to risk?