Descriptive Statistics: Reliability &
Validity
descriptive statistics - correct answer ✔✔statistics used to organize and describe data
measures of central tendency - correct answer ✔✔statistical methods for observing how data cluster
around the mean
normal distribution - correct answer ✔✔a symmetrical distribution with a single numerical
representation for mean, median, and mode
standard deviation - correct answer ✔✔represents the typical amount that a score is expected to vary
from the mean in a set of data.
percentile ranks - correct answer ✔✔scores that express the percentage of students who scored as well
as or lower than a given student's score
z-score - correct answer ✔✔derived scores that are expressed in standard deviation units, with a mean
of 0 and a standard deviation of 1
stanines - correct answer ✔✔a method of reporting scores that divide data into 9 groups and scores are
reported as 1 through 9 with a mean of 5.
deciles - correct answer ✔✔scores that are reported in 10 groups ranging from a score of 10 for the
lowest grouping to 100 for the highest group of scores, with each group representing 10% of the
obtained scores
raw scores - correct answer ✔✔the first scores obtained in testing; usually represents the number of
items correct
Validity
descriptive statistics - correct answer ✔✔statistics used to organize and describe data
measures of central tendency - correct answer ✔✔statistical methods for observing how data cluster
around the mean
normal distribution - correct answer ✔✔a symmetrical distribution with a single numerical
representation for mean, median, and mode
standard deviation - correct answer ✔✔represents the typical amount that a score is expected to vary
from the mean in a set of data.
percentile ranks - correct answer ✔✔scores that express the percentage of students who scored as well
as or lower than a given student's score
z-score - correct answer ✔✔derived scores that are expressed in standard deviation units, with a mean
of 0 and a standard deviation of 1
stanines - correct answer ✔✔a method of reporting scores that divide data into 9 groups and scores are
reported as 1 through 9 with a mean of 5.
deciles - correct answer ✔✔scores that are reported in 10 groups ranging from a score of 10 for the
lowest grouping to 100 for the highest group of scores, with each group representing 10% of the
obtained scores
raw scores - correct answer ✔✔the first scores obtained in testing; usually represents the number of
items correct
