STATS T2

Question 1

standardised scores (z-scores)

Answer 1

Question 2

Z-Score Formula

Answer 2

Question 3

Falsifiability

Answer 3

capacity for some proposition, statement, theory or hypothesis to be proven wrong (through systematic empiricism) a basis provided by the null hypothesis

Question 4

null hypothesis

Answer 4

states the contrary of the experimental or alternative hypothesis

Question 5

falsifiable hypothesis

Answer 5

can be logically contradicted by an empirical test that can potentially be executed with existing technologies .

Question 6

What is meant by dispersion/variability around the mean?

Answer 6

Determining how the scores relate towards the mean score

Question 7

What are measures of variability?

Answer 7

Range Interquartile Range Standard deviation Sample variance if sd=0 so we square scores and then take the sum so negative scores become positive Absolute Mean Deviation SD but not squared which could= 0

Question 8

What are the mean and standard deviation in the standard normal distribution?

Answer 8

mean=0 and sd=1 → z-score standard score specifying the amount of distance of the sd

Question 9

What is the mean and the standard deviation of t-scores?

Answer 9

Mean = 50 SD= 100

Question 10

What is meant by sampling error?

Answer 10

Chance difference = the way some statistics naturally varies from sample to sample = in that it wll always deviate from the parameter it is the random variability = standard deviation of the sampling distribution

Question 11

What is the standard error of the mean?

Answer 11

The standard deviation / variability from the estimated parameter mean of the distribution

Question 12

What is the purposes of the standard error?

Answer 12

It gives us an indication of just how much the sample statistic might differ across the samples. It’s like a z-score for all the potential differences we could observe but would not go against the finding

Question 13

What are the logical steps of hypothesis testing?

Answer 13

Set up a research Hypothesis H1 Set up a null hypothesis H0 Get a sample and sample distribution of sample statistics (eg mean) und the H0 Calculate probability value of of sample statistic at least as large as the one obtained Reject or Fail to Reject H0

Question 14

What’s the philosophical hypothesis of the null hypothesis?

Answer 14

M1-m2 =0 has been proposed by Fisher With the logic that we can always show that something is false

Question 15

How do you calculate the IQR?

Answer 15

Order the scores Find the median location (N/2) Find the median of the upper and lower quartile N low /2; N high /2

Question 16

What do d= 1 and d= .5 indicate?

Answer 16

That the effect the difference is either twice or half as large as the standard deviation

Question 17

What are the absolute deviations from the mean?

Answer 17

X- Mean that’s why if we average and take the root of them we get the standard sample deviation

Question 18

When you collect data from a sample, the sample variance is used to ?

Answer 18

make estimates or inferences about the population variance and comparing the variance of samples helps you assess group differences

Question 19

How is the sample mean related to variance and standard deviation?

Answer 19

it is expanded on in the formulas for variance and standard deviation

Question 20

Which five steps need to be taken to calculate the sample variance?

Answer 20

1. The mean (∑ 𝑋 /N) 2. The Deviation from the mean X- (∑ 𝑋 /N) 3. Squared deviation from the mean (X- (∑ 𝑋 /N))^2 4. Find the sum for all scores and devide by N-1 5. Take the root to find the standard deviation or z-score

Question 21

The standard deviation is more informative about the variability than the variance.

Answer 21

False

Question 22

The standard deviation is expressed in larger units than the variance.

Answer 22

False because the root is taken

Question 23

What does the standard deviation tell me?

Answer 23

how far, on average, a value lies from the mean which is why it is derived from the variance (square root)

Question 24

Which graph describes a correct null hypothesis?

Answer 24

right

Question 25

The p-value can be defined as

Answer 25

the probability of obtaining a significant result when the null hypothesis is true