Flashcards in Midterm 1 Deck (52):

1

## which of the following is true about a 95 confidence interval of the mean of a given sample.

### There is a 95 chance that the population mean will fall within the limits of the confidence interval.

2

## What does a significance test tell us?

### There is an effect in the population of sufficient magnitude to be scientifically interesting.

3

## A type 1 error....

### We conclude that there is a meaningful effect in the population when in fact there is not

4

## A null hypothesis is....

### Predicts that the experimental treatment will have no effect.

5

## What does a box plot not display?

### The mean

6

## Which of the following is least affected by outliers....

### The median

7

## What does it mean when a researcher rejects a null hypothesis at the .05 level?

### There is less than 5% chance of getting such an extreme result by chance if the null hypothesis is true.

8

## The results of the study are not extreme enough to reject the null hypothesis...

### None of the above, the results are inconclusive.

9

## Failing to reject the null hypothesis when the research hypothesis is true is referred to as a...

### A type 2 error.

10

## In a histogram the vertical dimension shows....

### Frequency....

11

## In a distribution of Z scores the mean is always

### zero and the standard deviation is always 1

12

## Interval scales of measurment

### Have equal distant scales...

13

## example of a ratio scale

### Physical distance, there can be a true zero.

14

## The mean is an appropriate measure when....

### The data is normally distributed, interval or ratio scale, date in which the mean, median and mode are all equal.

15

## Small overlap

### Increase power

16

## A small sample size

### Decrease power

17

## A large population standard deviation

### Decrease power

18

## Using a higher significance level ex 99%

### Decrease power

19

## P-Value

### You can't be absolute

20

## Confidence level and power

### If you increase confidence level, you decrease power because you have to prove more.....

21

## P value

### You can use it to see if data is significant but can't say if it's true for certain.

22

## Repetition of experiment

### it doesn't matter independent won't increase power.

23

## Large N sample

### Sample means will be approximately equal to the population mean.

24

## larger N

### the more normal the sampling distribution

25

## You need to know the sample size and the population mean to determine the

### standard deviation

26

## SD goes up

### power goes down

27

## Sampling size goes up

### power goes up

28

## And =

### multiply

29

## The mean of a sample distribution is equal to

### population not sample mean.

30

## Confi int

### Consist of a range of values that act as good estimates of the unknown population parameter.

31

## Confi int

### A major factor in determining the length of a confidence interval is the size of the sample.

32

## Sampling observations

### From a sampling distribution comes from a theoretical population that is normally distributed.

33

## Normal distribution

### mean, median and mode is the same.

34

## Density

### The height of the curve at different values of X

35

## Bayes theorem

### A theorem that tells us how to accumulate information to revise est. of probabilities.

36

## Binomial distribution

### Deals with situations in which each of the independent trials results in one of two mutually exclusive outcomes.

37

## Q-Q

### Test for normal distribution

38

## Conditional probability

### One event will occur given that some other event occurred.

39

## innerfence

### 1.5x the interquartile range.

40

## Galton

### Gave the normal distribution a central role in psychological theory. Especially the theory of mental abilities.

41

## mu

### is the population mean.

42

## kernel density plot

### Ignore mean and standard deviation.

43

## Problem with histogram

### They lose the numerical value of the individual scores.

44

## Stem and Leaf

### Most significant digits are the stem, less significant are the leaves. Useful for comparing 2 dif distrubutions

45

## External validity

### random selection

46

## Internal validity:

### Random assignment

47

## Area under normal distribution equals

### 1

48

## Two purposes of inferential statistics

### Parameter estimation Hypothesis testing

49

## standard error of mean

### is the standard deviation of the distribution of sample means. When it is large, the means are widely scattered The standard error of mean provides a measure of how much distance is expected on average between sample means and

50

## Neyman and Pearso

### Type 1 and 2 error

51

## A Type I error

### α, is the probability of falsely rejecting the complementary hypothesis when it is true

52