chp.1,2,3,4 psychological stats
Confounding
out of control
research
1 ask a question 2 set up methods 3 measure 4 evaluate findings
population parameter
A characteristics (usually numeric) that describes a population is called
Experimental because the researcher claims to have demonstrated cause
A researcher demonstrates that eating breakfast in the morning can cause increased alertness throughout the day. What research design must the researcher have used in this example explain...
all the above qualitative nominal ungrouped
A researcher distributes frequencies into the following classes; absent tardy present. what type of data are distributed?
false
A researcher measures the following scores on the quiz: 0,3,7,3,5,4 and 6. In this example the mean is larger than the median
Sample A
A researcher measures the number of trials two samples of participants to master a new task. In both samples,SS= 240. Sample A consisted of 12 participants and Sample B consisted of 18 participants. Which sample is associated with the largest variance.
Histogram
A researcher measures the weight (in ounces) of newborn infants in one month of March. WHat type of graphical display would be most appropriate for summarizing the frequency of infants falling into different intervals of weight.
Yes, Because the sample size is equal in this example
A researcher selects a sample of 6 professors, 6 students, and 6 administrators at a local school and has them rate the effectiveness of an innovative new teaching style. In this example, it is possible that the wm ratings will equal the arithmetic mean for the entire sample of 18 participants.
cocaine dependent and inexperienced Impulse behavior
A researcher test whether cocaine use increases impulsive behavior in a sample of cocaine independent and cocaine inexperienced mice identify the independent variable identify the dependent variable
population sample
A stats class has 25 students enrolled but 23 students attended class
Calculating the mean
Add all the numbers and then divide by the number of how many there are.
true
Descriptive stats can be used to describe population and samples of data
Interval variables
Do not have a true zero
to ensure that a single score cannot be counted in more than one interval
Frequency data are not always distributed in intervals.What types of data are not distributed in intervals?
midpoint and upper boundary
Frequency polygons are plotted at_____ whereas ogives are plotted as the ______ of each interval
false
Graphs, tables and summary stats all illustrate the application of inferential stats.
true
Inferential stats are procedures used to make inferences about a population ,given, only a limited amount of data
data is skewed or ordinal data
Median is the appropriate measure for describing what type of data?
true
One reason the denominator for sample variance is (n-1) is because this makes it unbiased estimator of the population variance.
Nominal, Ordinal,Interval,and ratio
Rank the scales of measurement in order from least to most informative
N
Sample SIze
equal
The definition formula____ the computational formula for SS
Ratio
The most informative scale of measurement
false
The population mean is used to estimate the value of the sample mean.
coding
The procedure of converting a categorical variable to numeric values
N; n
The size of a population is symbolized as_____ whereas the size of a sample is symbolized as___?
false
The sum of the frequencies for a distribution is 100. The means that fewer than 100 people were counted.
negative
The variance and standard deviation can never be.
false
The weight in pounds of a newborn infant is an interval scale of measurement.(cant be negative in weight)
variance of sample will equal the variance of the population from which the sample was selected on average
What does it mean to say that the sample variance is unbiased?
standard deviation measures the average distance that scores deviate from their mean
What does standard deviation measured?
Grouped data is distributed in intervals ungrouped are not
What is the key distinction between ungrouped and grouped data?
includes all scores to estimate variabillity
Why is variance as a measure of variability preferred to the range the IQR and the SIQR
The number of employees that work under an employee
You are interested in measuring the construct, work experience. Which of the following measures for this construct is qualitative and discrete?
Central Tendency
a description of all scores in a distribution mean median and range
Inferential
always take data from a larger population and makes inferences
nominal
basic random name
Quasi- exp
cant randomly assign an assignment
parameters
capture every person
exp
cause and effect
operational definition
define what variables are
Ratio variable
do have a true zero
research design
experiment some measure of control random assignment random selection indp. variable and dependent
Sample discrete population categorical
how do sample and population mean differ?
two scores the largest and smallest scores in a distribution
how many scores are included to compute the range?
raw score
individual measurement
mode
more than one peak or number and nominal date
mean
nominal distribution, ratio, data or average
ordinal
order name date
Dependent variable
performance , what is being measured
descriptive
quantify measured behavior and attitudes also provided by a clear summary of the data verify
correlation
relations
interval
time and space
Median
used in place of mean in case of skewed ranked data or ordinal date
Continuous and Discrete
what are two types of variables that can be quantitative?
Independent variable
what you manipulate
The weighted mean equals the arithmetic mean when the sample sizes are weights for a set of scores are the same or equal
when is the weighted mean equal to the arithmetic mean for combining the two or more samples?