Statistics Modules Vocab Flashcards
Standard error of the mean
the standard deviation of a sampling distribution of the mean.
Degrees of freedom
the number of values in the final calculation of a statistic that are free to vary. The number of independent ways by which a dynamic system can move, without violating any constraint imposed on it, is called number
Dispersion
how stretched or squeezed a distribution (theoretical or that underlying a statistical sample) is
Type I error
rejecting the null hypothesis when, in fact, the null hypothesis is true.
Type II error
failing to reject the null hypothesis when, in fact, the null hypothesis is false.
p-value
the probability of obtaining an effect as extreme as results given that the null hypothesis is true
Critical Region
?
t-test
an inferential statistical test often used to determine whether there is a statistically significant difference between the means of two groups of scores for the same variable.
t-test for independent samples
compares the means between two unrelated groups on the same continuous, dependent variable
paired-samples t-test
compares two means that are from the same individual, object, or related units
analysis of variance (ANOVA)
collection of statistical models used to analyze the differences among group means and their associated procedure
chi-square
n
Power
probability of rejecting the null hypothesis when alternative is true
Exploratory data analysis
analyzing data sets to summarize their main characteristics, often with visual methods - enables seeing what the data can convey
Bar graph
a diagram in which the numerical values of variables are represented by the height or length of lines or rectangles of equal width.
Line graph
uses line segments to connect data points and shows changes in data over time.
Scatter plot
a graph in which the values of two variables are plotted along two axes, the pattern of the resulting points revealing any correlation present.
Pie graph
n
Frequency distribution
table that displays the frequency of various outcomes in a sample
Histogram
graphical representation of the distribution of numerical data; estimate of the probability distribution of a continuous variable
Skewed distribution
A distribution is negatively skewed, or skewed to the left, if the scores fall toward the higher side of the scale and there are very few low scores.
Normal distribution
a function that represents the distribution of many random variables as a symmetrical bell-shaped graph.
Outlier
an observation point that is distant from other observations. May be due to variability in the measurement or it may indicate experimental error
Resistant measure
n
Measure of central tendency
n
Measure of spread
n
Interquartile range
n
Boxplot
n
Phi coefficient
n
Linear regression
n
Least-square regression line
n
Regression weight
n
Correlation matrix
used to investigate the dependence between multiple variables at the same time. The result is a table containing the correlation coefficients between each variable and the others.
