Chapter 2 Flashcards
raw score
is a data point that has not yet been transformed or analyzed
frequency distibution
describes the pattern of a set of numbers by displaying a count or proportion for each possible value of a variable
frequency table
is a visual depiction of data that shows how often each value occurred, that is, how many scores were at each value. Values are listed in one column, and the numbers of individuals with scores at that value are listed in the second column.
grouped frequency table
is a visual depiction of data that reports the frequencies within a given interval rather than the frequencies for a specific value
histogram
looks like a bar graph but is typically used to depict scale data with the values of the variable on the x-axis and the frequencies on the y-axis
frequency polygon
is a line graph with the -axis representing values (or midpoints of intervals) and the y-axis representing frequencies; a dot is placed at the frequency for each value (or midpoint), and the dots are connected
normal distribution
is a specific frequency distribution that is a bell-shaped, symmetric, unimodal curve
skewed distribution
is a distribution in which one of the tails of the distribution is pulled away from the center
positively skewed data
the distribution’s tail extends to the right , in a positive direction
floor effect
is a situation in which a constraint prevents a variable from taking values below a certain point
negatively skewed data
have a distribution with a tail that extends to the left, in a negative direction
ceiling effect
is a situation in which a constraint prevents a variable from taking on values above a given number
stem and leaf plot
is a graph that displays all the data points of a variable (or of two levels of a variable) both numerically and visually
