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MSwithin reflects...
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error
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Homogeneous
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Similar in makeup
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Systematic Sample
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Every "nth" person participates
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null hypothesis
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hypothesis to be tested
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Multicollinearity
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x values are correlatedcan cause problemsdon't assume they are and then throw them outIf the sign is backwards (-) means they may be tied togetherWill have to illiminate one and keep the othersIf you leave it, it inflates the standard error of the estimate
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1.They help us identify outliers.2.They tell us how well the measure of central tendency summarizes the entire distribution.3. They are used to compute other statistics.4.They can be theoretically important in and of themselves
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Define range
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regression
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process of finding a regression equation
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Standard Normal Curve/ Distribution
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symmetrical, bell-shaped, central tendency to middle, most fall b/w -1 & +1
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five number summary
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Distribution consists of the following 1 lower value2 lower value3 median4 upper Quartil5 high quartil
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Case-Control Study
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A retrospective study in which subjects who have a response outcome of interest (the cases) and subjects who have the other response outcome (the controls) are compared on the explanatory variable.Ex. The brain cancer-cell phone usage example.
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Response error
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error due to respondents reporting information that is not truthful, and nonresponse error is error due to differences between those who responded to the survey and those who did not respond.
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multiplication rule
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method for finding the probability that both of two events occur
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Control Group
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Experimental units assigned to a baseline treatment level
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how would being wider affect a curve
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larger variability
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relative frequency
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proportion or percentage of the data value that falls in categoryRelative Freq= Freq in categoriey ------------------- total freq
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Sample
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the part of the population from which we actually collect information used to draw conclusions about the whole
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Statistic
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A characteristic of a sample; a number computed from sample data (without any knowledge of the value of a parameter) used to estimate the value of a parameter. Examples include x-bar , the sample mean, and s, the sample standard deviation.
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population
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all the cases in a group from which samples maybe drawn for a study
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Research is important if 3. Unimportant if 3.
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1)Clarify relationship amoung variables 2) Support only one hypothesis 3) answer leads to practical application. 1) answer already firmly established 2)variables are known to have a small effect/ theoritcal interest 3)variables not believed to be causally related
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Correlated Groups t test
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•Typically used to analyze the relationship between two variables under the following conditions:
oIf the dependent variable is quantitative in nature in nature and is measured on a level that at least approximates interval characteristics
oThe independent variable is within subjects in nature
oThe independent variable has two, and only two, levels
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range
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set of all values attained by a given function throughout its domain
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Symmetric Data
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The mean and the median are about the same.
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law of large numbers
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the theorem in probability theory that the number of successes increases as the number of experiments increases and approximates the probability times the number of experiments for a large number of experiments.
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population mean
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the mean of data set is the average of all of the values
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The One-Sample t Test
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The One-Sample t test should be used in place of a z score conversion when the standard error of the mean (σ) is unknown.
If you look at the equation to calculate a t score, it is almost exactly the same as the z score conversion, with the exception of the denominator, in which you use the estimated standard error of the mean
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Why do we need a null hypothesis
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In behavioral research, you can never actually prove that something is true, but we can prove that it’s false.
Provides a starting point for any statistical test
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General idea of what outliers do to your data
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•If you have 1 outlier compare it with the data and compare it without during correlation
•Can cause a strong correlation to appear weak and vice versa
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Binomial Variance
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np(1-p)
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Class width
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max-min/number of classes
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MSbetween reflects...
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treatment effects + error
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factor
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Another term for explanatory variable.
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Ratio scales
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Magnitude, equal intervals, absolute zero
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Elements
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entities on which data are collected
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Unexplained variation
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the sum of squared residuals
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Hawthorne Effect
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Subjects change their behavior because they know they are in an experiment
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line chart
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distrobutions of quantitative data as a series of dots onnected by lines
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The 11thperson was probably an outlier, possibly yielding misleading results.
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Define regression
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census
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attempt to contact every individual in the entire population
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independent variable
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variable whose value determines the value or values of other variables
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Experiments
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Study in which subjects are randomly assigned to treatments
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Trend
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Long term, more than a year (t)=time variable=is used to find trent
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Symmetric
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If neither tail of the histogram is longer than the other.
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SS total
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the total variability in the dependent variable
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Matched pairs
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Either two measurements are taken on each individual such as pre and post OR two individuals are matched by a third variable (different from the explanatory variable and the response variable) such as identical twins or windows matched by installer when comparing installation time of two brands of windows.
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individual
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the basic unit (or subject) of the experiment upon which a treatment is applied
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cicero is doing a study to find the average life of indoor cats vs outdoor cats. what type is he performing?
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t-test
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Coefficient of Variation
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Used to compare dispersion in data sets with dissimilar sets of measurement. It is the the standard deviation expressed as a percent of the mean.
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Unbiased Estimator
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A sample mean is an Unbiased Estimator of the population mean
An unbiased estimator of a population parameter is a statistic whose mean across all possible random samples of a given size equals the value of the parameter.
(There are going to be some higher and some lower so it all equals out)
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marginal Distribution
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The distribution of the values in the "total" row (or the "total" column) of a two-way table.
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Crossover Design
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A type of matched pair design in which subjects \"cross over\" during the experiment from using one treatment to using another treatment.
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Sample mean, x bar
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the random variable of the sampling distribution of x bar.
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a systematic sample
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since we are selecting every k = 13th invoice.
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The probability of rejecting a false null hypothesis; computed as 1 – β. Increase power by increasing sample size.
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A difference between the observed statistic and the claimed parameter value that is large enough to be worth reporting. To assess practical significance, look at the numerator of the test statistic and ask ‘Is it worth anything?’ If yes, then results are also of practical significance. Note: Do not assess practical significance unless results are statistically significant.
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Sampling Distribution of x bar
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A list of all the possible values for x bar together with the frequency (or probability) of each value; in other words, the distribution of all x bars from all possible samples.
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rooney is using a ztest to determine if the new turtle feed is worth the extra money. he already gathered raw scores. what is his next step
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to find the distance from the mean and to find the zscore
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