Stats (Scales of Measurement, Descriptive Statistics) Flashcards
of the four scales of measurement, the ________ scale is the least mathematically complex
nominal
when we measure a characteristic with a nominal scale, there is no inherent _______ to the scale categories, and we cannot say that one person has more or less of the characteristic being measured than the other person
order
the only quantitative operation that we can perform when data are measured on a nominal scale is to count the _______ of observations in each category
frequency (number)
As its name implies, the ordinal scale of measurement had the mathematical property of ______
order
when using an ordinal scale, we can say that one person has ______ of the characteristic being measured than another person
more or less
The interval scale is more mathematically complex than the ________
ordinal scale
the interval scale not only has the property of _______ but also the property of ______ intervals between successive points on the measuring scale. As a results, we can conclude that a score of 100 is _____ between the scores of 90 and 110
order; equal; midway
the most mathematically complex measurement scale is the ______ scale.
ratio
the ratio scale has the properties of order and equal intervals as well as an ________ zero point. The latter property makes it possible not only to add and subtract scores but also to ______ them and to conclude that a person who receives a score of 150 has ______ times as much of the characteristic being measured as a person who receives a score of 50
absolute; multiply and divide; three
A frequency polygon can be described in terms of it’s shape. A normal distribution is symmetrical and _______ shaped
bell
distributions can deviate from the normal. When a distribution is more “peaked” than the normal distribution, it is said to be ______. When a distribution is flatter than the normal distribution, it is ____________
leptokurtic; platykurtic
distributions can also be asymmetrical. In a ______ distribution, over 50% of the scores fall on one side of the distribution
skewed
when scores are concentrated in the positive side of the distribution with only a relatively few scores in the negative side (tail), the distribution is said to be _______ skewed
negatively
when scores are concentrated in the negative side of the distribution with only a relatively few scores in the positive side (tail), the distribution is called ______ skewed
positively
the mean, median, and mode are measures of ______ tendency that summarize a distributions of data by providing a “typical” score
central
the mode is the most _______ occurring score or category in a distribution
frequently
the median is the _______ score in and ordered set of data
middle
the mean is the arithmetic _______
average
the mean can be calculated only when the variable has been measured using a(n) _______ scale
interval or ratio
in a normal distribution, the three measures of central tendency are equal to the same value. However, in a _____ skewed distribution, the mean is greater than the median, which is greater than the mode
positively
in a ______ skewed distribution, the mean is less than the median, which is less than the mode
negatively
measures of variability indicate the degree of _______ in a distribution of scores.
dispersion (heterogeneity)
the simplest measure of variability is the _______, which is calculated by subtracting the lowest score in the distribution from the _______ score
range; highest
the variance and standard deviation are more thorough measures of variability because their calculation includes ____ of the scores in the distribution
all
variance and standard deviation measures indicate, on the average, how much the scores in a distribution vary from the distribution’s ________
mean
The standard deviation is equal to the _______ of variance
square root
the standard deviation is usually preferred to the variance as a descriptive technique because it expresses a distribution’s variability in the same unit of ______ as the original scores and is easier to interpret
measurement
if a distribution of IQ scores has a mean of 100 and a variance of 225, its standard deviation is equal to ____. Assuming that the population distribution is normal, this means that, in the population, about ______ percent of people have IQ scores between 85 and 115; about _______ percent have scores between 70 and 130; and about _____ percent have scores between 55 and 145
15; 68; 95; 99
when a constant is ______ each score in a distribution, the measures of central tendency change but the measures of variability stay the same
added to or subtracted from
when each score is _____ by a constant, the measures of central tendency are variability all change
multiplied or divided
For children with ADHD, an academic achievement test has a mean of 40 and a standard deviation of 8. Assuming that the distribution of scores is normally shaped, you can conclude that 16% of these children obtained scores below a score of:
32
In a leptokurtic distribution:
a larger proportion of scores are located in the middle of the distribution than they are in a normal (mesokurtic) distribution.
In a negatively skewed distribution of scores:
the median is greater than the mean (In a negatively skewed distribution, most scores are “piled up” in the positive tail while a relatively few scores are in the negative tail. Because the mean is more sensitive to the magnitude of all scores, it is affected more by the low scores in the negative tail and is lower in value than the median or the mode. Therefore, the median is greater than the mean in a negatively skewed distribution.)
To be able to conclude that one research participant has twice as much of a characteristic than another participant, your measure of that characteristic must produce scores that represent which scale of measurement?
ratio
