Measures of center and spread
The arithmetic average of a distribution, obtained by adding the scores and then dividing by the number of scores.
What is the Mean?
Every member of the population has a known and equal chance of selection.
What is a Simple Random Sample?
A bias caused by a number of people who did not respond to the survey
What is Non-Response Bias?
The hypothesis that states there is no difference between two or more sets of data in a significance test
What is a Null Hypothesis?
A graphed cluster of dots, each of which represents the values of two variables.
What is a Scatterplot?
All possible outcomes of an experiment
What is Sample Space?
Experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which is assumed to be an active agent.
What is the Placebo Effect?
The middle score in a distribution; half the scores are above it and half are below it.
What is Median?
A sample drawn by selecting individuals systematically from a sampling frame.
What is Systematic Sample?
Occurs when some groups in the population are left out of the process of choosing the sample.
What is Undercoverage?
The hypothesis which states the Null Hypothesis is incorrect in a significance test.
What is the Alternative Hypothesis?
A bar graph that shows the frequency of data within equal intervals.
What is a Histogram?
An error that occurs when a researcher concludes that the independent variable had an effect on the dependent variable, when no such relation exists; a false positive.
What is a Type l Error?
Probability based on what happens when an experiment is actually done.
What is Experimental Probability?
The datum which occurs the most in a set of data.
What is Mode?
The random assignment of subjects to treatments is carried out separately within each block.
What is Block Design?
Bias introduced to a sample when individuals can choose on their own whether to participate in the sample.
What is Voluntary Response Bias?
A parameter of the t distribution. When the t distribution is used in the computation of an interval estimate of a population mean
What is Degrees of Freedom?
A graphical representation of a quantitative data set. Leading values of each data point are presented as stems and second digits are given as leaves.
What is a Stem and Leaf Plot?
An error that occurs when a researcher concludes that the independent variable had no effect on the dependent variable, when in truth it did; a false negative.
What is Type ll Error?
Data identified by something other than numbers
What is Qualitative?
A measure of variability that describes an average distance of every score from the mean (r).
What is Standard Deviation?
The population is divided into strata and a random sample is taken from each stratum.
What is a Stratified Sample?
Anything in the survey design that influences the responses from the sample.
What is Response Bias?
When your discovered p-value is less than your alpha (.05 if not given). States that chance alone would rarely produce an equally extreme result.
What is Statistical Significance?
The line that minimizes the sum of squared residuals
What is a Least Squares Regression Line (LSRL)?
An unintended difference between the conditions of an experiment that could have affected the dependent variable.
What is a Confounding Variable?
The distribution of values taken by the statistic in all possible samples of the same size from the same population.
What is a Sampling Distribution?
A descriptive feature in which describes the range of the data graphically.
What is spread?
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.
What is Matched Pairs Design?
A type of response bias where the question is posed to achieve a desired result.
What is Wording Bias?
The probability of getting a result at least as extreme as the result given from the test. The lower the value the stronger the evidence.
What is a p-value?
Displays the 5-number summary as a central box with whiskers that extend to the non-outlying data values.
What is a Boxplot?
The sampling distribution of the mean will approach the normal distribution as n increases (n>30).
What is the Central Limit Theorem?
Range of the middle 50% of the values; Q3-Q1 = 75th percentile - 25th percentile.
What is the Interquartile Range (IQR)?
An extreme deviation from the mean
What is an Outlier?
A sampling design in which entire groups are chosen at random.
What is a Cluster Sample?
A variable other than x and y that simultaneously affects both variables, accounting for the correlation between the two.
What is a Lurking Variable?
uses sample data to test hypotheses about the shape or proportions of a population distribution. The test determines how well the obtained sample proportions fit the population proportions specified by the null hypothesis.
What is a Chi-Squared Goodness of Fit Test?
A table containing counts for two categorical variables. It has r rows and c columns.
What is a Two-Way Table?
An experiment in which a set number of trials is used
An experiment in which there is no set number of trials but is ended by achieving an outcome.
What is the Geometric?