Statistics

Question 1

What are the 5 steps in the Scientific Method?

Answer 1

Question 2

True or False?

The research question is always about the sample size.

Answer 2

False

The research questions are always about the population.

Question 3

Why do we use Inferential Statistics?

Answer 3

We are unable to test our whole population or do the same test multiple times. Inferential Statistics (P Value) allows us to determine the probability of an effect on a population without testing the whole lot.

Question 4

What are examples of a nominal set of data?

Answer 4

1. Gender
2. Hair colour

Characteristics

1. Must be unordered - not higher or valued more than any other
2. Must be categorical - distinct groups

Question 5

What are examples of an ordinal set of data?

Answer 5

1. Level of education - High school, tafe, uni
2. Karate levels - White, brown, blue etc.

Characteristics

1. Ordered categories

Question 6

What are examples of an interval set of data?

Answer 6

1. IQ results

Characteristics

1. No meaningful 0 point

Question 7

What are examples of a ratio set of data?

Answer 7

1. Age - 1, 2 , etc

Characteristics

1. Has an absolute 0
2. Must be numerical

Question 8

What is the difference between a univariate and a bivariate summary?

Answer 8

Univaritate - One variable

Bivariate - Comparing two variables.

Question 9

What is a qualitative variable?

Answer 9

It is categorical (written)

e.g. hair colour, type of pet etc.

Question 10

What is a quantitative variable?

Answer 10

It is a numeric variable

e.g. age, height, weight etc.

Question 11

What does this picture represent?

Answer 11

It shows sampling variability.

There will be variability across samples. BUT if we take the average of all these scores, it will be a representation of our population

Question 12

If your p-value is 0.8, would you reject the H0?

Answer 12

Yes, the further away from 0.05, reduces the likelihood that H1 is supported

Question 13

What are the five steps to testing a hypothesis using a computer program?

Answer 13

1. Decide on alpha
2. Calculate test statistic
3. Calculate p-value from test statistic
4. Compare p-value with the alpha level
5. If the p-value is:
   
   1. Less than 0.05 (alpha) reject H0
   2. Greater than 0.05 (alpha) don’t reject H0

Question 14

What are the 6 types of statistical tests we have learnt?

Answer 14

1. 1-sample t-test
2. Independent samples t-test
3. Paired samples t-test
4. Pearson’s correlation
5. Chi-squared goodness of fit test
6. Chi-squared test of independence

Question 15

If you have one numeric variable and you are comparing the mean of this variable to another known mean, what statistical test would you conduct?

Answer 15

One-sample t-test

Question 16

If you have one categorical variable and you are comparing the proportions of this variable to known proportions, what statistical test would you conduct?

Answer 16

Chi-square goodness of fit test

Question 17

If you have two numeric variables and you are testing the strength of a linear relationship, what statistical test would you conduct?

Answer 17

Pearson’s correlation

Question 18

If you have one numeric and one categorical variable and comparing the mean score between two independent groups, what statistical test would you conduct?

Answer 18

Independent samples t-test

Question 19

If you have one numeric and one categorical variable and comparing the mean score between two related ​groups, what statistical test would you conduct?

Answer 19

Paired t-test

Question 20

If you have two categorical variables and comparing categories of one variable across categories of another variable, what statistical test would you conduct?

Answer 20

Chi-square test of independence

Question 21

What number shows that the effect size remains unchanged?

a) d=0.2
b) d=0.08
c) d=0.6
d) d=0.05

Answer 21

a) d=0.2

Question 22

A psychologist is interested in the effect of high-sugar snacks on children’s attention at school. She hypothesises that students who eat high-sugar snacks will be less attentive after the break than students who eat healthy snacks.

Which of the following is the null hypothesis?

Select one:

a. students’ degree of attention will influence their subsequent snack choice
b. students who eat high-sugar snacks will be less attentive after the break than students who eat healthy snacks
c. students who eat high-sugar snacks will be no more or less attentive after the break than students who eat healthy snacks
d. students’ attention will differ between those who eat high-sugar snacks and those who eat healthy snacks

Answer 22

C

The correct answer is: students who eat high-sugar snacks will be no more or less attentive after the break than students who eat healthy snacks

Question 23

researcher was interested in the effects of gender on attitudes about gun control. The researcher surveyed a group of individuals, 12 of whom were men and 12 of whom were women. In this example, what is the INDEPENDENT variable?

Select one:

a. The 12 men in the study
b. Participants’ attitudes about gun control
c. The 12 women in the study
d. The gender of participants

Answer 23

D

The correct answer is: The gender of participants

Question 24

True or False: Parameters are numeric summaries of the SAMPLE.

Answer 24

False

Question 25

A researcher is interested in the relationship between individuals’ personality and their level of attachment to their pets. She finds 10 pet owners and administers a survey, which asks them to report on their personality (specifically, degree of extraversion) and dimensions of their love for their pet. In this example, an example of a variable is: Select one: a. The researcher b. The individual pet owners c. Their level of extraversion d. The data collected (survey responses)

Answer 25

C The correct answer is: Their level of extraversion

Question 26

In a taste test challenge, tasters try to identify different types of coffee under "blind" conditions, where they can't see the products. Tasters are given one type of coffee (from the following options: regular latte, decaf latte, mocha, or a dirty chai) to try. They then have to select which drink they think they received. How many levels are there to the independent variable? Select one: a. 2 b. 1 c. 3 d. 4

Answer 26

D 4

Question 27

You want to assign a label to variable t1. Which of the following highlighted sections of the Stata interface would we do this in? Select one: a. Box C b. Box D c. Box B d. Box A

Answer 27

The correct answer is: Box D

Question 28

I want to type some syntax (code) directly into Stata to produce a summary table of the variables. Which of the following highlighted sections of the Stata interface would I do this in? Select one: a. ‘Command’ b. ‘Variables’ c. ‘Properties’ d. ‘Review’

Answer 28

The correct answer is: ‘Command’

Question 29

Consider the following statement about string-type variables in Stata. True or false: All data should be entered into the data sheet as string-type variables Select one: True False

Answer 29

False

Question 30

The statement “There is some difference in test scores between the two groups” is most representative of which of the following? Select one: a. Alternate hypothesis b. Research question c. Research hypothesis d. Null hypothes

Answer 30

The correct answer is: Alternate hypothesis

Question 31

A z-score of 0 represents: Select one: a. This score is below the mean b. There is no score c. This score is above the mean d. This score is equal to the mean

Answer 31

The correct answer is: This score is equal to the mean

Question 32

After running a statistical test, the researcher makes a conclusion to not reject the null hypothesis. Given that, which of the following is correct? Select one: a. This proves the null hypothesis is true b. This proves the alternate hypothesis is true c. This proves the theory that she is testing is incorrect d. This means there is no support for the alternate hypothesis

Answer 32

The correct answer is: This means there is no support for the alternate hypothesis

Question 33

A type 2 error is: Select one: a. Rejecting the research hypothesis when we should not reject it b. Concluding that the sample does not reflect the population c. Rejecting the null hypothesis when we should not reject it d. Not rejecting the null hypothesis when we should reject it

Answer 33

The correct answer is: Not rejecting the null hypothesis when we should reject it

Question 34

A researcher has collected health data from a random sample of Australian adults. She wants to compare the average IQ to existing (known) information on the average (mean) IQ of adolescents from the USA, to see whether the population of Australian adolescents are more intelligent, on average, compared to the population of USA adolescents. Which of the below is the most appropriate method to use to address this question? Select one: a. Calculate the median Australian IQ from the sample and see if it is numerically smaller than the average USA IQ b. An independent samples t-test c. Calculate the mean Australian IQ from the sample and see if it is numerically smaller than the average USA IQ d. A one-sample t-test

Answer 34

The correct answer is: A one-sample t-test

Question 35

Generally speaking, the larger the obtained t statistic: Select one: a. The larger the critical t statistic b. The smaller the critical t statistic c. The larger the p-value d. The smaller the p-value

Answer 35

The correct answer is: The smaller the p-value

Question 36

A decision to reject H0 (the null hypothesis) can be interpreted as: Select one: a. The probability of obtaining the test statistic is less than .05 b. The sample is statistically not significantly different from the population c. The proportion of the sample equals the mean of the sample d. The probability of obtaining the test statistic is greater than .05

Answer 36

The correct answer is: The probability of obtaining the test statistic is less than .05

Question 37

Have a look at the output below. A p-value of p = .0127 (found in the middle down the bottom of the screenshot) corresponds with which type of alternate hypothesis? Select one: a. a non-directional alternate hypothesis b. either directional or non-directional c. neither directional or non-directional d. a directional alternate hypothesis