Exam 9: Principles of Research Design and Statistical Preliminaries for Analyzing Bivariate Relationships

The normality and homogeneity of variance assumptions relate only to samples,not to the populations from which the samples were drawn.

For many observational independent variables,only between-subjects designs are applicable.

The experimenter will manipulate the_____.

Random assignment _____ that the research groups will not differ beforehand on the _____ variable.

A common strategy to control confounding variables is (are):

A confounding variable is one that is related to the independent variable (the presumed cause)and that affects the dependent variable (the presumed effect),rendering a relational inference between the independent variable and the dependent variable ambiguous.

A(n)_____ strategy is one where a set of procedures or manipulations is performed in order to create different values of the independent variable for the research participants.

An experimental strategy is a set of procedures which creates different values of ____.

What are the relative strengths and weaknesses of between-subjects versus within-subjects designs?

_____ statistics focus on differences between distributions of scores and can be used to analyze quantitative variables that are measured on an _____level.

Which of the following applies to a disturbance variable?

Distinguish between an experimental strategy and an observational strategy.

What is the major disadvantage of holding a variable constant?

Since observational independent variables will always be confounded with all other variables that are naturally related to them,_____ are typically not possible when an observational strategy is used.

Another term used for within-subjects design is ____________________.

One potential problem with within-subjects designs is the fact that the treatment in the first condition may have _____ effects that influence performance in the second condition.

Since random assignment cannot be applied to observational groups,observational independent variables will always be _____ with all other variables that are naturally related to them.

An investigator was interested in determining if the size of a coin influenced judgments of numerosity when people were asked to make judgments of how many coins were in a pile of coins.Fifteen subjects were asked to estimate the number of pennies in a display of 43 coins.In another condition,15 different subjects estimated the number of dimes for the same display.In the above experiment,the size of the coin is also related to its value.Value is thus a ____.

A developmental psychologist's is studying at what age children develop a fear of strangers.She studies infants at 2 months old (n=8)and than again at 6 months old (n=8)and measures how fearful they are to strangers.Using a scale of (0=no fear to 5=very afraid).What type of experimental design is she using?

On what basis are we able to make a causal inference about the relationship between variables?