Hypotheses, Descriptive Statistics and Presenting Data

Question 1

What should we consider when choosing a plot type for presenting data?

Answer 1

The data type

Question 2

What plot type is used for a numerical (continuous or discrete) variable to see how the data is distributed?

Answer 2

Histogram

Question 3

What types of numerical variables can we use a histogram for?

Answer 3

We can use a histogram for both continuous and discrete numerical variables

Question 4

What type of plot should we use for presenting two numerical variables?

Answer 4

We should use a scatterplot

Question 5

Can we use a scatterplot for both continuous and discrete numerical variables?

Answer 5

Yes, we can use a scatterplot for both continuous and discrete numerical variables

Question 6

How should we arrange the variables on a scatterplot?

Answer 6

• independent variable = x axis
• dependent variable = y axis

Question 7

What type of plot should we use for presenting one categorical and one numerical variable?

Answer 7

A boxplot

Question 8

What types of categorical variables can we use a boxplot for?

Answer 8

• regular
• ordinal
• binary

Question 9

What types of numerical variables can we use a boxplot for?

Answer 9

• continuous
• discrete

Question 10

How should we arrange the variables on a boxplot?

Answer 10

• categorical variable = x axis
• numerical variable = y axis

Question 11

What type of plot should we use for presenting two categorical variables?

Answer 11

If only a small number of levels (groups), a table is appropriate otherwise use a grouped bar chart

Question 12

How many levels (groups) can a table accommodate for presenting two categorical variables?

Answer 12

A table can accommodate a small number of levels (groups)

Question 13

What type of plot should we use for presenting two categorical variables when there are many levels (groups)?

Answer 13

A grouped bar chart

Question 14

Can we use a grouped bar chart for other types of variables, such as numerical variables?

Answer 14

No, a grouped barchart is specifically for presenting two categorical variables with many levels (groups). For numerical variables, we would use other types of plots such as histograms, boxplots, or scatterplots

Question 15

What is the difference between descriptive and inferential statistics?

Answer 15

• Descriptive statistics = summarising a collection of data, graphically or numerically, and performing exploratory analyses (e.g. plots)
• Inferential statistics = estimating parameters and their confidence limits, as well as hypothesis testing

Question 16

What is the purpose of descriptive statistics?

Answer 16

To summarise and describe the important features of a dataset (e.g. central tendency and spread of the data)

Question 17

What is the purpose of inferential statistics?

Answer 17

To make inferences about a larger population based on a sample of data

Question 18

What are some examples of exploratory analyses in descriptive statistics?

Answer 18

Creating:
- histograms
- scatterplots
- boxplots
to visualize the distribution and relationships between variables.

Question 19

What is hypothesis testing in inferential statistics?

Answer 19

Testing a hypothesis about a population parameter based on a sample of data, and determining the likelihood of obtaining the observed results if the null hypothesis (i.e., no difference or no relationship) were true.

Question 20

What does central tendency refer to in descriptive statistics?

Answer 20

Central tendency in descriptive statistics refers to the measure of the “middle” or “typical” value of a dataset.
- e.g. mean, median, and mode

Question 21

What does spread refer to in descriptive statistics?

Answer 21

How spread out or dispersed the data is
-e.g. range, variance, and standard deviation