another name for qualitative variables (are not numeric variables)
non-numeric data (e.g. color)
numeric variables (they can be continuous variables)
used for mutually exclusive random events. the chance of at least one of them occuring is the sum of their individual probablities.
a research hypothesis; the hypothesis that is supported if the null hypothesis is rejected
a graphic that displays how data falls into different categories or groups
the consistent underestimation or oversestimation of a true value, because of preconceived notion of the person sampling the population
curve with two equal scores of highest frequency
event with only two possible outcomes
binomial probablitiy distribution
for binomial events, the frequency of the number of favorable outcomes. For a large number of trails, the binomial distribution approaches the normal distribution
involving two varibales, especially, when attempting to show a correlation between two variables.
a graphic display of data indicating symmetry and central tendency
Central Limit Theorem
a rule that states that the sampling distrubution of means from any population will be normal for large sample "n"
a probability distribution used to test the independence of two nonimal variables
the number of observations that fall into each class interval
categories or groups contained in frequency graphics
coefficient of determination
a measure of the proportion of each other's variablility that two variables share
the range of values that a population parameter could take at a given level of significance
the probablity of obtaining a given result by chance
a variable that can be measured with whole numbers and fractional (or decimal) parts thereof
two(or more) quantities that change together in a consistent manner. Thus, if the value of one variable is known, the other can be immediately determined from their relationship
a measure of the degree to which two variables are linearly related
the value of a conmputed statistic used as a threshold to decide whether the null hypothesis will be rejected.
degrees of freedom
a parameter used to help select the critical value in some probablility distribution
events such that the outcome of one has an effect on the probablity of the outcome of the other
a variable that is caused or influenced by another
numberical data that describe phenomena
the distance of a value in a population or sample from the mean value of the population or sample
a test opf the prediction that one value is higher than another'; also called a one-tailed test
a variable that can be measured only by means of whole numbers; or one which assumes only a certain set of definite values, and no others
both outcomes unable to happen at the same time
a collection of meansurements; how scores tend to be dispersed about a measurement scale
a graphic that displays the variablity in a small set of measures
a mistake encountered in calculating the probablility of at least one of several events occuring, when the events are not mutually exclusive. In this case, the addition rule does not apply
a rule that is dounded on observation, without a theoretical basis. Or a "rule of thumb"
the frequency of occurence of the values of a variable. For each possible value of the variable, there is ana ssociated frequency with which the variable assumes that value
a graphic that displays how many measures fall into different classes, giving the frequency at which each category is seen observed
a graphic presentation of frequency of a phenomenon that typically uses straight lines and points
data that has eben sorted into categories, usually in order to construct a frequency histogram
a set of values that belong to the same class
a graphic presentation of frequency of a phenomenon
events such that the outcome of one has no effect on the prbabality of the outcome of the other
a variable that causes, or influences, another variable
conclusion about a population parameter bases upon analysis of a sample statistic. Inferences are always stated with a confidence leve
the value of "y" at whcih a line crosses the vertical axis
set of measures lying between the lower quartile (25th percentile) and the upper quartile (75th percentile), inclusive.
a scale using numbers to rank order; its intervals are equal but with an arbitrary zero point
both outcomes happening simultaneously; P(AB)
any line-fitting or curve-fitting model that minimizes the squared distance of data points to the line
(Q1) the 25th percentile of a set of measures
the sum of the measures in a distribution divided by the number of measures; the average
measures of cnetral tendency
descriptive measures that indivate the center of a set of values, for eample, mean median, and mode
measures of variation
descriptive measures that indicate the dispersion of a set of values, for example, variance, standard deviation, and standard error of the mean
the middle measure in an ordered distribution
(Q2) the 50th percentile of a set of measures; the median
most frequent measure in a distribution; the high point on a frequency distribution
the probability of two or more independent events all occuring is the product of their individual probabilities
events such that the occurence of one precludes the occurence of the other
a relationship between two variables such that when one increases, the other decreases
negatively skewed curve
a probabalility or frequency distribution that is not normal, but rather is shifted such that the mean is less than the mode.
a scale using numebrs, symbols, or names to desginate different subclasses
a test of the prediction that two values are equal or a test that they are not equal;a two-tailed test
statistical test used when assumptions about normal distrubution in the population cannot be met, or when the level of measurement is ordinal or less. For example the z-square test
smooth bell-shaped curve symmetrical about the mean such that its shape and area obey the empirical rule
the reverse of the research hypothesis. It is directly tested by statistical analysis so that it is either rejected or not rejected, with a confidence level. If it is rejected, the alternative hyposthesis is supported
statistical parameters presented as numbers (as opposed to pictorial statistics)
a graph that displays a running total
a test of the prediction that one value is higher than another
a scale using numbers or symbols to rank order; its intervals are unspecified
a data point that falls far from most other points; a score extremely divergent from the other measures of a set
a charateristic of a population. The goal of statistical analysis is usually to estimate population parameters, using statistics from a sample of the population
Pearson's product moment coefficient
indentical to the correlation coefficient
the calue in an ordered set of measurements such that P% of the measures lie below that value
statistical parameters that are presented as graphs or charts (as opposed to simply as numbers)
a graphic that displays parts of the whole, in the form of a cirle with its area divided appropriately
a number computed froma sample to represent a population parameter
a group of phenomena that have something in common. the population is the larger group, whose properties (parameters) are estimated by taking a smaller sample from within the population, and applying statistical analysis tot he sample
a relationship between two variables such that when one increases, the other increases, or when one decreases, the other decreases
positively skewed curve
a probability of frequency distribution that is not normal, but rather is shifted such taht the mean is freater than the mode.
the probability that a test will reject the null hypothesis when it is, in fact, false.
a quantitative measure of the chances for a particular outcome or outcomes
a smooth curve indicating the frequency distribution for a continuous random variable
for a binomial random even, the probability of a successful (or favorable) outcome in a single trial.
phenomenon measured in kind, that is, non-numberical units. For example, because it cannot be expressed simply as a number
phenomenon measured in amounts, that is, numerical units. For eample, length is a quanitative variable.
an event for which there is no way to know, before it occurs, what the outcome will be. Instead, only the probabilities of each possible outcome can be stated.
error that occurs as a result of sampling variability, through no direct fault of the sampler. It is a reflection of the fact that the sampler. It is a reflection fot ehf act that the sample is smaller than the population; for larger smaples, the random error is smaller
difference between the largest and smallest measures of a set
a scale using numbers to rank order; its intervals are equal, and the scale has