Biostat test - Các loại biến số

Các loại biến số

Categorical variables

1. Select all of the following variables that are examples of categorical variables:

A.   Number of episodes of disease in a patient over a year

B.   Serum bilirubin level

C.   Gender

D.   Severity of haemophilia (mild/moderate/severe)

E.   Reduction in blood pressure following antihypertensive treatment

Numerical variables

2. Select all of the following variables that are examples of numerical variables:

A.   Number of episodes of disease in a patient over a year

B.   Serum bilirubin level

C.   Gender

D. Severity of haemophilia (mild/moderate/severe)

E. Reduction in blood pressure following antihypertensive treatment

Ordinal variables

Select all of the following statements which you believe to be true. An ordinal variable is one for which:

A. The data are discrete and can take one of many values.

B. The data are continuous and follow an ordered sequence.

C. The data are categorical.

D. The categories of response are ordered.

E. There can only be two categories of response.

Nominal variables

Select all of the following variables which are measured on a nominal scale.

A. Height in cm.

B. Ethnic group 

C.   Social class (I/II/III-N/III-M/IV/V)

D.   Age categorised as young, middle-aged or old.

E.   Age in years.

Types of variable

5. Select all of the following statements which you believe to be true.

A.   A nominal variable has categories that can be ordered in some way.

B.   Quantitative data occur when the variable takes some numerical value.

C.   An ordinal variable relates to a particular type of numerical data.

D.   A binary categorical variable can be either nominal or ordinal.

E.   Nominal data are usually measurements of some type.