PSYC 300 chapter 1&2
why is the standard deviation more often used as a descriptive statistic than the variance
The standard deviation gives a more direct sense of the variability of the data since it has the same dimensions as the data values themselves rather than the squares of the data values
in samples the mean is represented by
X̅ or M
A participant in a cognitive psychology study is given 50 words to remember and later asked to recall as many of the words as she can. She recalls 17 words. what is the variable?
amount of words that the participant can recall
susan collected data from 76 students who filled out a questionnaire about exercise and GPA. from the exercise portion, students were classified as sedentary, moderate, or vigorous exercisers. what is the independent variable
exercise classification
describe the general shape of the distribution for a histogram that has more large bars on the left hand side of the graph.
it is skewed to the right
what is definition of standard deviation?
it is the average amount that the amount of increase in activation differs from the mean value
what is the definition of mean?
it is the average or center value in the distribution of the amount of increase of whatever someone is looking at
describe variance
it is the average squared deviation from the mean
describe standard deviation
it is the square root of the variance or roughly the average deviation from the mean
to show the relationship between serial position of words on a list and errors, the proper graph is a ___ graph
line
skewed and multimodal distribution in a graph will have
many different curves
for continuous data that are positively skewed, the ___ is usually smaller than the ___
mean, median
the ___ is the high point in the distribution's histogram
mode
what is the measure of central tendency for nominal variables
mode
psychologists measure parenting style as: authoritarian, authoritative, and permissive. parenting style is measure with a ___ variable
nominal
unimodal and symmetrical distribution in a graph will have
one curve at the top; you can draw a line through it and it would be even on both sides
for ____ data, a median is an appropriate measure of central tendancy
ordinal
what value describes a population
parameter
grouped frequency distributions and simple frequency distributions differ in
range of scores covered by the distribution
on a ____ scale, zero means that no amount was present
ratio
a ____ is a characteristic of a sample
statistic
A client rates her satisfaction with her vocational counselor as a 3 on a 4-point scale from 1=not at all satisfied to 4=very satisfied. what is the variable?
the client's satisfaction with her vocational counselor
janna gathered data from 47 students, who filled out self-consciousness scale. scores in this scale range from 0-66. in addition, janna classified each student's height as shore, average, or tall. what is the dependent variable?
the self-consciousness scale
a bimodal distribution in a graph will have
two curves at the top
in populations the mean is represented by
μ
in which of the following examples is the median the preferred measure of central tendency?
-distribution of annual household income -distribution of the number of children in a household
A participant in a cognitive psychology study is given 50 words to remember and later asked to recall as many of the words as she can. She recalls 17 words. what are the possible values?
0-50
A client rates her satisfaction with her vocational counselor as a 3 on a 4-point scale from 1=not at all satisfied to 4=very satisfied. what are the possible values?
1, 2, 3, 4
if the standard deviation is 4, the variance is
16
A participant in a cognitive psychology study is given 50 words to remember and later asked to recall as many of the words as she can. She recalls 17 words. what is the score?
17
A client rates her satisfaction with her vocational counselor as a 3 on a 4-point scale from 1=not at all satisfied to 4=very satisfied. what is the client's score?
3
from Janna's experiment, what is the number of levels of the independent variable?
3
what is meant by a symmetrical unimodal distribution?
A distribution is a pattern of frequencies for the various values of a variable collected in a study. A symmetric unimodal distribution is a distribution where there is one value with a larger frequency than any other and the pattern of frequencies on the left and right of this larger frequency are mirror images of each other.
what is meant by a negatively skewed unimodal distribution?
A negatively skewed unimodal distribution is a distribution in which the left side of the distribution is long and spread out, somewhat like a tail. On the right side of the distribution, there is one value that clearly has a larger frequency than any other value.