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?