Basic Stats

Which is the probability of getting two events if you replace the first even back into the population?

Between groups variance is variance you ___ and within group variance is variance that you ___

We are more likely to know ____ because we set alpha before the study

Select all the tests that are between-subjects

The SE of sampling is __ the pop. SD when sample size is greater than 1

Z-scores are standard scores

Scatterplots are used in correlation

Experiments are when groups are pre-existing

What is the middle number of the distribution?

Between subject designs protect against carryover effects

What is the second step of the scientific research method?

Which scale represent the distance between the numbers are equal (Likert scales)

What is the average score of the distribution?

For this class, bivariate relations are represented with:

The Tukey CD helps you to compare the ___ of each group in your ANOVA

Select all the tests that are within-subjects

Critical Difference (CD) is the smallest difference between two sample means needed to infer that pop. means are diff.

Select all the tests that have 1 level of IV

z=\left(\frac{X-µ}{σ}\right)is the equation for converting raw scores into z-scores

s.hat_{xbar}=\frac{s.hat}{\sqrt{N}} is used to estimate population SD in t-test, then use t=\frac{xbar-μ}{s.hat_{xbar}}

Correlated groups t-test has a ___ design and independent groups t-test has a ___ design

What are extraneous variables in research?

As one variable increases, so does the other

Which sign do we use to estimate the population mean (We use sample to est. pop.; Greek = pop. & normal letters = samp.)

Chi-square is used when both variables are qualitative (nominal) and between subjects

Each participant is in only one comparison group (receives only one level of the IV)

Probabilities range from:

Which is the probability of getting two events if you don't replace the first even back into the population?

Independent groups t-test has a degrees of freedom of N - 2

The best predictor of someone's score on a DV when you have no IV is the mean of the DV

In this class, IV are usually qualitative and DV are quantitative

Sampling error:

Interval and Ratio are quantitative (can do math on it)

2, 3, 5, and 10 are psychologically pleasing group sizes for making groups in stats

In this class, we've only learned a 2x2 chi-square, so critical value is always +3.841

Within subject designs are said to have more power than between subject designs

What is the third step of the scientific research method?

Most people stack up around the higher scores for negative skew

Which scale means that the numbers represent the name/labels of the group the participants are assigned to (cat vs. dog)

Which scale means that the numbers represent the rank the participants are assigned to (oldest to youngest sibling)

Which graph do you use for quantitative variables?

Degrees of freedom (DF):

What is the most common number or category?

Each person's scores is called an observation, represented with the letter X in statistics

AKA Repeated Measures. All participants are in all groups (they receive all levels of the IV)

Nominal and Ordinal scales are qualitative (can't do math on it)

Non-experiments are when the researcher creates groups and randomly assigns people to them

What is the first step of the scientific research method?

Non-experiments are always between-subject designs

The closer you are to -1 or +1, the stronger the correlation coefficient

What is the fifth step of the scientific research method?

The central limit theorem states that the mean of the distribution of means is equal to the mean of the population

What is the fourth step of the scientific research method?

Select all the tests that have 3 levels of IV

For every comparison you make using a t-test, alpha increases by multiplying the alpha by the number of comparisons

Beta and R-square are effect sizes

σ_{xbar}=\left(\frac{σ}{\sqrt{N}}\right)is the equation for standard error for one-sample z-tests

Cohen's d measures:

Reasons that psychology uses statistics:

Which is not a scale of measurement?

Pick a nominal variable (quiz)

We typically want __ power bc it is the probability of finding a significant result when you should (think .05 v. .01)

What is the difference between the highest and lowest number?

Which scale represent the distance between the numbers are equal and has a true 0 (money)

Probability has a probability of ___

As one variable increase the other decreases

What differs one-sample t-test from one-sample z-tests?

Mean = Median = Mode

Which graph do you use for qualitative variables?

Rejecting the null, when you should have fail to reject (null is true; false positive)

Tukey tests compare two group means to each other and find out if the means are diff. enough to be stat. diff.

The two types of tables for quantitative variables are ungrouped (less than 10 values) and grouped (more than 10)

In one-sample t-test, degrees of freedom is equal to N-1

Select all the tests that have 2 levels of IV

As compared to between-subjects designs, within subjects designs...

Select the factor that will increase statistical power

Most people stack up around the lower scores for positive skew (ex. F-scores)

What is frequency?

Most people score around the mean; 50% fall at or below the mean

Disturbance variable is when it looks like it affects the DV, but the DV is really caused by another IV

Failing to reject the null, when you should have reject (null is false; false negative)

In science we assume that the null hypothesis (H0) is true (believe in H1, but test H0)

Correlations is the only test (we've learned) that is used for two quantitative variables

Which sign do we use to estimate the population SD (We use sample to est. pop.; Greek = pop. & normal letters = samp.)

2σ is a common criterion for a score being rare

Select the qualitative variable