section exam 2
There are ______ regression equations for two correlated variables.
2
The statistic used to determine whether a linear relationship exists between two interval/ratio variables is the
Pearsons r
Type 1 error
Rejecting null hypothesis when it is true
alternative hypothesis
a prediction of what the research expects to happen in the study
null hypothesis
a statement or idea that can be falsified, or proved wrong
Edna compares two groups and finds a Cohen's d of .18, suggesting that the means of the groups differ by ______, which is a ______ effect.
.18 standard deviation units; weak
A double-blind experiment helps reduce __
demand characteristics and experimenter expectancy effects
A sampling distribution is created by
drawing many samples of the same size from a population and computing the same statistic for each sample
probability theory
examines random events that, when repeated, establish a pattern, based on this pattern we can establish how probable certain results are
The critical value of a statistic defines the
extreme 5% of the distribution for a one-tailed hypothesis and extreme 2.5% of the distribution for a two-tailed hypothesis
type 2 error
failing to reject a false null hypothesis
The 99% confidence interval will be ______ the 95% confidence interval.
larger than
Confidence Interval (CI)
margin of error
In order to compute a one-sample t test we must _____
measure our variable on an interval or ratio scale
Two ways a researcher can reduce the probability of a Type I error are to use a ______.
more stringent criterion level and a two-tailed test
A null hypothesis is always stated in terms of _
no difference between groups or no relationship
One of the assumptions of the one-sample t test is _
normally distributed population
Degrees of freedom represent the
number of scores free to vary in a sample
A Type I error occurs when you _
reject a true null hypothesis
All other things being equal we prefer a ______ confidence interval because ______.
smaller; it suggests our results are closer to the true population mean difference
Diffusion of treatment occurs when
the treatment administered to one group is shared with another group through cross-group interactions
The critical t value for p < .05 represents the
value that defines the extreme 5% of the distribution defined by the null hypothesis
two-tailed hypothesis
A hypothesis that predicts a relationship between two variables but does not specify the direction of the relationship.
Power is defined as
correctly rejecting a false null hypothesis
inferential statistics
statistical analysis of data gathered from a sample to draw conclusions about a population from which the sample is drawn
Sequencing
the organization of curriculum content into an order which progresses from simple to more complex
The purpose of inferential statistics is to allow researchers to determine whether ______.
the outcome of a study is typical or unusual for a particular sampling distribution
hypothesis testing
the process of determining the probability of obtaining a particular result or set of results
One reason to use a correlational design is
when an experimental study would be unethical
Individual differences within the sample such as age, gender, and education level can create uncontrolled differences in the measure of our study. This difference is called ______ variance, and it can ______ the power of our study.
within-groups or error; decrease
