| Define Bi-variate Data | when there are data from two variables for the same subject |
| what are categorical variables? | data values that are names or labels, such as sex (male, female) or coffee size (small, medium, large). |
| Describe numerical variables | data values that are numbers, usually resulting from counting or measuring, such as number of brothers (0, 1, 2, …) or hand span (cm). |
| What are the names of the 2 types of numerical data. How are they different? | continuous variables which represent a quantity that is measured rather than counted, for example the weights of people in kilograms, and
discrete variables which represent a quantity that is determined by counting, for example,
the number of people waiting in a queue. |
| What is association between variables? | the values of one variable relate in some way to the values of the other.
Essentially, association means the values of one variable generally co-occur with certain values of the other. |
| The question "Are younger people more likely to believe in astrology" is investigating the association between which 2 variable types? | numerical - age
categorical - belief in astrology |
| What is the second step in investigating the association between 2 variables? | to determine
which of the two variables is the explanatory variable and which is the response variable. |
| How is the response variable determined | A response variable is the variable that “responds” to changes you make in the explanatory variable |
| How do you know you have identified the explanatory variable | the explanatory variable (EV)
is the variable we expect to explain or predict the value of the response variable (RV). |
| A farmer is investigating whether a fishes toxicity can be predicted from its colour. Identify the RV and EV | RV - toxicity
EV - colour |
