psych stats

Ace your homework & exams now with Quizwiz!

to construct a sampling distribution you must

(1) identify the mean of the sampling distribution (2) compute the standard error of the mean (3) distribute the possible sample means 3 SEM above and below the mean.

3 characteristics of the sample mean

-is an unbiased estimator -follows central limit theorem -has a minimum variance

standard error calculated

-is the population standard deviation divided by the square root of the sample size.

h1

alternative hypothesis

law of large numbers

increasing the number of observations or samples size will decrease standard error. the smaller the standard error, the closer a distribution of sample means will be from the population mean

cohen's d

measures the number of standard deviations an effect an effect shifted above or below the population mean stated by the null hypothesis.

standard error

standard deviation of sample means is measured by the _____ of the mean.

effect

difference between sample mean and population mean stated in null hypothesis

type 2

failure to reject a false hypothesis.

N! / n! (N-n)!

formal for determining the number of samples of any size that can be selected from a population

one tailed tests

greater power. if value stated in null hypothesis is false, this test will make it easier to detect and reject. but difficult to justify. do not double for this

type 1

incorrect rejection of a true null hypothesis

characteristics of the sample variance

-it is an unbiased estimator when we divided SS by df (or n-1) -distribution of this follows the skewed distribution rule -distributions of this has no minimum variance when we divide SS by df

sample variance

-the ___________ is an unbiased estimator when we divided SS by df (or n - 1) -distribution of the sample variances follows the skewed distribution rule -distribution of sample variances has no minimum variance when we divided SS by df.

sampling distributions

a distribution of all the sample means or variances that could be obtained in samples of a given size from the same population

vary far

although the sample variance equals the population variance on average, the distribution of all other sample variances can _________ from the population variance when you divided SS by df.

experimental theory is for

behavioral research

level of significance

criterion of judgement upon which a decision is made regarding the value stated in the null

compute the test statistic

is step 3 of hypothesis testing. the value of it can be used to make a decision regarding null hypothesis. helps determine how likely the sample outcome is if the population mean stated in the null is true.

two tailed tests

more conservative more difficult to reject null hypothesis eliminates possibility of type III error

h0

null hypothesis

standard deviation

of sample means is measured by the standard error of the mean. is calculated by the square root of the variance.

what do you not double p value

one tailed tests.

central limit theorem

regardless of the distribution of sample means selected from that population will be approximately normally distributed.

effect size

size of an effect in a population -how far scores have shifted in the population -percent of variance that can be explained by a given variable -most meaningfully reported with significant effects (decision to reject null)

as population standard deviation decreases

standard error decreases

as sample size increases

standard error decreases

null hypothesis

statement about the population parameter (such as the mean) that is assumed to be true. -starting point to determine if null is likely to be true or not. example: children in the united states watch an average of 3 hours of TV per week

alternative hypothesis

statement that contradicts the hypothesis we think null is wrong, allows us to state what we think is right

theoretical theory is for

statistical theory

variance

the _______ of the sampling distributions of the sample means is minimal.

smaller the standard error

the closer a distribution of sample means will be from the population mean

sampling error

the extent to which sample means selected from the same population differ from one another.

experimental sampling

the order of selecting individuals does not matter and each individual selected is not replaced before sampling again used in behavioral research

theoretical sampling

the order of selecting individuals matters an each individual selected is replaced before sampling again basis for statistical theory

reject null when

the sample mean is less than 5%,

skewed distribution rule

the sampling distribution of sample variances tends toward a positively skewed distribution, regardless of the distribution in the population.

normal distribution

the theoretical distribution with data that are symmetrically distributed around the mean, median and mode

5%

what the level of significance is usually set as


Related study sets

II Lecture Chapter 15 Short Answer/Discussion pp 337

View Set

Abeka 10th Grade Algebra 2 Test 03

View Set

Introduction to Nonprofit Organizations Midterm

View Set

A&P L.9 (ANATOMY AND POSITIONING OF THE FOREARM AND ELBOW)

View Set

Management of Patients With Urinary Disorders

View Set

BIBL 104-Quiz: The Old Testament Books of Prophecy

View Set

East Asia (Midterm/Final Notes) [FIU - ASN 3410]

View Set