Quizzes-Statistics

The distribution of sample means is the collection of sample means for ALL possible random samples of a particular size (n) that can be obtained from a population.

True

The least squares solution is used to calculate the amount of error based on the distance between data points and your regression line.

True

The null hypothesis states that there is no difference between your population and sample (or your control vs. treatment groups).

True

The shape of the z-scores will have the exact same shape as the original distribution of sores.

True

The standard error tells you how much error to expect when using a sample mean to represent a population

True

Variance is the average squared distance from the mean.

True

We use an ANOVA instead of multiple t-tests to reduce the experimentwise alpha.

True

You can use either a t-statistic or F-ratio to evaluate the significance of a correlation.

True

You should use the pooled variance to calculate your standard error for two-sample independent t-tests because of bias.

True

You use a t-statistic (using t-test) instead of a z-statistic to perform a hypothesis test when you do not have the population standard deviation.

True

What percent of values fall within 3 standard deviations of the mean?

99.7%

Degrees of freedom describe the number of scores in a sample that are free to vary.

True

Post-hoc tests are additional hypothesis tests conducted after an ANOVA to determine exactly which mean differences are significant.

True

Standardized scores let us compare scores from different scales (i.e., depression scales vs. anxiety scales).

True

The z-score distribution will always have a mean of ___.

0

Which of the following would be considered a large effect in terms of percentage of variance explained?

0.29

A repeated-measures design study comparing two samples uses _____ groups of participants and obtains ____ score(s) for each participant.

1,2

If your sample size is 108 what is your df?

107

In a sample of n=10 scores the smallest score is x=8 and the largest is x=20. What is the range of the sample?

12

The distribution of means based on a sample size of 45, pulled from a population distribution with a mean of 100 and a standard deviation of 15, would have a standard error of:

2.24

What is the standard error for sample with a standard deviation of 25 and n = 100?

2.5

In a two-factor ANOVA, how many sets of hypotheses (null & alternative) will you have?

3

"If you have a regression equation Y=4x+3, what is your Y-value when your X is 8? "

35

What is the test score for an individual with a z-score of -1.5 in a classroom with a mean score of 60 and a standard deviation of 10?

45

A sample of n=4 and standard deviation (s) = 10. What is the estimated standard error?

5

"What is the value of (x-2) for the following scores: 6, 2, 4, 2?"

6

Bobby has a test score of 50 and a z-score of -2. The standard deviation of the class is 5. What is the mean of the class?

60

What percent of values fall within 1 standard deviation of the mean?

68%

A main effect means that there are significant differences due to _________.

A factor

"If you had a correlation of 0.89, how would you describe the strength of the correlation?"

A positive strong correlation

Which of the following is an example of an independent-measures design?

A study comparing the self-esteem of 10-year-old boys and 10-year-old girls

"What are the assumptions for both the repeated-measures and two-factor, independent measures ANOVA?"

All of the above

How can you measure the effect size?

All of the above

Larger sample variances affect your hypothesis test by...

All of the above

The between treatment variance encompasses variance from which of the following?

All of the above

What are the assumptions for the repeated-measures ANOVA?

All of the above

What information do you need to determine the critical region for a t-test?

All of the above

Which of the following is a characteristic of a correlation?

All of the above

Which of the following statements about the distribution of sample means is correct:

All of the above

Which of these do we use to describe data?

All of the above

An effect size is important because _____.

All of the answers

Which of the following is power affected by?

All of the answers

A null hypothesis for an ANOVA would be _____.

All three means are the same

A repeated-measures ANOVA is used to evaluate mean differences in which general research instance(s)?

Both of the above

The alternative hypothesis for a repeated-measures ANOVA states that "at least one treatment mean is different from another."

True

A _____ is composed of means based on samples rather than raw scores.

Distribution of means

Random sampling requires that each indiviual in the population has an _______________ of being selected.

Equal chance

An ANOVA uses _______ for its test statistic.

F-ratio

Which of the following is a type II error?

Failing to reject the null hypothesis when the alternative hypothesis is true.

"A repeated-measures design deals with the differences of the means, while an independent-measures design deals with the mean of the differences."

False

"Correlation equals causation, meaning you can deduce a cause-and-effect relationship based on a correlation. "

False

"If your calculated test statistic is located out of your critical region, you reject the null hypothesis."

False

"When you graph the interaction of factors and the lines are parallel, that means that there is an interaction effect. "

False

A repeated-measures ANOVA is beneficial because it increase the number of participants necessary for the study.

False

A repeated-measures design is better than an independent-measures design because it requires more subjects.

False

A two-factor ANOVA will always have four cells

False

As sample size increases, there is more error between the sample mean and the population mean.

False

If I am interested in studying a certain population, every sample of that population will have the same mean.

False

It is okay to have a non-normal population distribution with a small sample size.

False

Levels are the groups being compared and are made up of factors.

False

One-tailed and two-tailed hypothesis tests have different null hypotheses.

False

Post hoc tests for a repeated measures are conducted in the exact same manner as post hoc tests for a one-way ANOVA (i.e. no substitution in the formulas)

False

The first step to a hypothesis test is to collect the data.

False

The only explanation for observed differences between groups is the treatment.

False

The predicted value based on a regression equation is a perfect prediction.

False

The same critical F value is always used to determine whether the main effect for Factor A, the main effect Factor B and the interaction effect are significant.

False

The z-scores do not form a standardized distribution.

False

The central limit theorem suggests that the distribution of sample means for a sample size n will approach a normal distribution as n approaches ____.

Infinity

Matching

Look at quiz 2

Which measure of central tendency is also known as the average?

Mean

The within-groups DF is _____ and the between-groups DF is ______.

N-k,k-1

A _________ is when you mathematically control for the influence of a third variable in a correlation.

Partial correlation

The variables height and weight are examples of

Quantitative data

Which of these is NOT a measure of central tendency

Range

What do you need to be aware of when using regression equations for predictions?

Range restriction

"When conducting a repeated-measures ANOVA, what is calculated to measure the individual differences?"

SS between subjects

"After you remove the individual differences in a repeated-measures ANOVA, what are you left with?"

SS error

"IQ tests are standardized so that the average score is 100 for the entire group of people who take the test each year. However, if you selected a sample of 20 people who took the test and computed their average IQ score, you probably would not get 100. What statistical concept explains the difference between your sample mean and the mean for the entire group?"

Sampling error

__________ is the naturally occurring discrepancy that exists between a sample statistic and the corresponding population parameter

Sampling error

The z-scores measure the number of ______________ a value is away from the mean.

Standard deviations

The term _____ is used for the distribution of means in place of the term standard deviation.

Standard error

In a repeated-measures ANOVA, any differences that between treatments can be explained by what two factors?

Systematic differences caused by the treatment and random differences

Which of the following is NOT an assumption of hypothesis testing with 2-sample independent t-tests.

The number of observations within each sample must be 200

What is the value represented by lowercase letter n?

The number of scores in a sample

The p-value is equivalent to ________.

The proportion in the tail of your z-score

Which of the following is not an assumption of hypothesis test?

The sample size is at least 100

"A matched-subjects design has two different samples, but the individuals in the first sample are matched with an individual in the second sample. "

True

"A repeated-measures t-test is also called a within-subjects, paired, or dependent t-test. "

True

"Correlation measures the linear relationship between two variables, while a regression analysis precisely defines this line. "

True

"Significance or alpha is determined by the researcher, meaning it can be whatever the research wants it to be."

True

"You have to find the F-critical for each effect when running a two-factor, independent measures, ANOVA. "

True

A repeated-measures ANOVA removes the variance due to individual differences when calculating the F-statistic.

True

A type I error is a false positive.

True

An ANOVA compares differences between two or more groups.

True

An interaction effect means that the combination of factors creates a different result.

True

CI stands for confidence interval.

True

Can you have an interaction effect without having a main effect for either factor?

Yes

Larger sample sizes affect the outcome of your hypothesis test by...

creating larger t-statistics

"__________ is the plural form of __________, which refers to a single observation or measurement."

data; datum

"Statistical techniques that summarize, organize, and simplify data are classified as __________."

descriptive statistics

How do you measure effect size for the repeated-measures ANOVA?

eta^2

Statistical techniques that make inferences to the population using sample data are classified as __________.

inferential statistics

Which ANOVA notation represents the number of groups/treatments/conditions in your study?

k

A researcher finds that the average SAT score of newly admitted students at UH is 1100. The college board says the average score for all american college students is 1000. The average score of 1000 is an example of a _____ and the average score of 1100 is an example of a ____

parameter;parameter

A researcher is curious about the average IQ of registered voters in the state of Florida. The entire group of registered voters in the state of Florida is an example of a __________.

population

The variables favorite pizza topping and ice cream flavor are examples of

qualitative data

Within-treatment variance measures differences caused by ________.

random, unsystemic factors

Match the following: Data from a group of individuals Data from a group of samples Data from an individual

sample data population data raw data

A __________ is a set of individuals selected from a __________

sample; population

"A researcher is interested in the sleeping habits of American college students. A group of 50 students is interviewed and the researcher finds that these students sleep an average of 6.7 hours per day. For this study, the group of 50 students is an example of a __________ and the average of 6.7 hours is an example of a __________."

sample; statistic