1statement of the possible difference or relationship between the variables
alternative hypothesis
2predicts that there will be a difference between 2 groups and specifies how they will differ
one-tailed (directional)
3expressed in Z values and determines the rejection region
critical values
4state the hypothesis testing steps
1. state the null hypothesis (Ho) and alternative hypothesis (Ha)
2. determine the appropriate test statistic
3. determine the critical value, degree of freedom (n-1), level of significance, sample size, one-tailed or two-tailed
4. collect data and compute the value of the test statistic
5. make a statistical decision
6. state the conclusion
5What are the two types of errors in hypothesis testing (describe them)
type 1 error - when Ho is rejected when the null hypothesis is true
tyep 2 error - when Ho is acceptedetained when the null hypothesis is false
6We always evaluate the results of an experiment by assessing the?
null hypothesis
7why do we directly assess the null hypothesis instead of the alternative hypothesis?
so that we can calculate the probability of chance events
8is there a way to calculate the probability of the alternative hypothesis
none
9how do we evaluate the null hypothesis?
by assuming it is true and testing the resonablenes of this assumption by calculating the probability of getting the results if the chance alone is operating
10If the obtained probability turns out to be equal to or less than a critical probability level called the alpha (a) level, we __ the null hypothesis
reject
11Rejecting the null hypothesis allows us, then, to accept indirectly the ___ hypothesis because, if the experiment is done properly, it is the only other possible explanation
alternative
12When we reject HO, we say the results are ? We do not state: We accept the alternative hypothesis.
significant or reliable
13Also known as the Level of Significance.
a level
14Refers to the degree of significance which we accept or reject the null
level of significance
15the degree of significance which we accept or reject the null is usually around _%-_%; hence a.01 or a.05.
1% - 5%
16If the obtained probability is eqial to or less than the level of significance?
reject HO
17If the obtained probability is greater than the level of significance?
fail to rejectetain HO
18what is the goal of estimation?
Same as that in hypothesis testing which is to learn more about the value of a mean or mean difference in a population of interest.
19Statistical procedure in which a sample statistic is used to estimate the value of an unknown population parameter.
parameter estimation
20how do we use estimation?
To use estimation, we select a sample, measure a sample mean or mean difference, and then use that sample mean or mean difference to estimate the value of a population parameter.
21Statistic that estimates some fact about the population. You can also think of an estimator as the rule that creates an estimate.
estimator
22The quantity that is being estimated (i.e. the one you want to know
estimand
23Either an underestimate or an overestimate
Biased Estimates
24Accurate that neither underestimates or overestimates
Unbiased Estimates
25Use of a sample statistic (e.g. a sample mean) to estimate the value of a population parameter. Usually a single value estimate of a parameter.
Point Estimation
26Statistical procedure in which a sample of data is used to find the interval or range of possible values within which a population parameter is likely to be contained. Includes a range of values where the parameter is expected to lie.
Interval estimation
27Probability or likelihood that an interval estimate will contain an unknown population parameter (e.g., a population mean).
level of confidence
28Tells you how sure you can be and is expressed as a percentage.
level of confidence
29In a hypothesis test, the __, alpha, is the probability of making the wrong decision when the null hypothesis is true.
significance level
30Interval or range of possible values within which an unknown population parameter is likely to be contained.
Confidence Interval
31Upper and lower boundaries of a confidence interval given within a specified level of confidence.
Confidence limitsoundaries