Introduction to Biostatistics

Question 1

Define statistics

Answer 1

The scientific study of numerical data based on natural phenomena.

Question 2

With the definition of statistics, biostatics can then said to be?

Answer 2

The application of statistical methods to the solution of biological phenomena

Question 3

What does biostatics help one identify?

Answer 3

Patterns of importance in nature and life.

Question 4

To accepted as scientific evidence what criteria must statistics meet? (2)

Answer 4

1. Be objective
2. Adhere to general ethical code of scientific methodology

Question 5

Give one example of a general ethic required in scientific methodology.

Answer 5

Reproducibility

Question 6

What does the term natural phenomena mean?

Answer 6

It applies to all events that occur in biotic and abiotic factors outside control of human beings.

Question 7

Do events evoked by scientists during experiments count as natural phenomena? Yes or No

Answer 7

Yes they do.

Question 8

What is data?

Answer 8

collection of facts and figures/information that can be in any form—numerical or non-numerical

Question 9

What data does statistics generally deal with?

Answer 9

variables obtained a collection of individual observations

Question 10

In statistics, how are observations expressed?

Answer 10

Objectively quantified with degree of belief or disbelief expressed as a probability.

Question 11

In statistics objects/phenomena under study can be classified as populations, samples and individual. Define what population is?

Answer 11

Collection of individuals under consideration in a statistical study.

Example 1000 tomatoes

Question 12

What then is a sample?

Answer 12

A collection of individuals selected from a population by specified procedure.

Example, 100 tomatoes from population of 1000 tomatoes

Question 13

What then is an individual?

Answer 13

The smallest sampling unit.

example, 1 tomato

Question 14

The property measured from the individuals under consideration is the?

Answer 14

Variable.

E.g. Weight of tomatoes

Question 15

In light of individuals under consideration, what is a variable in statistics?

Answer 15

A shared property which differs in some measurable way from individual to individual.

E.g. weight

Question 16

What are the two types of variables?

Answer 16

1. Quantitative
2. Qualitative

Question 17

What are qualitative variables and give two examples.

Answer 17

They are non-numerical values

E.g. name of a restaurant
blood type

Question 18

List the types of numerical/quantitative variables. 4. Think of a table of variables of eg wildlife survey.

Answer 18

1. Continuous - a measurement of sth
2. Discrete/categorical/nominal - a count of sth
3. Attributes
4. Derived

Question 19

How are continuous variables quantified?

Answer 19

They are measured i.e. ascertain the size, amount, or degree of (something) by using an instrument or device marked in standard units.

Question 20

What is a defining characteristic of continuous variables? Think time, continuous

Answer 20

They are infinite/ have no end

Question 21

Give three examples of continuous variables.

Answer 21

1. Time
2. Length
3. Weight

Question 22

How are discrete variables quantified?

Answer 22

They are counted

Question 23

Discrete values are also known as?

Answer 23

Categorical or ordinal or nominal

Question 24

Give an example of a discrete variable

Answer 24

Number of red cars or number of students

Question 25

Attribute variables are ranked according to the attributes or characteristics of individual. True or false?

Answer 25

True

Question 26

Define derived variables.

Answer 26

Variables based on relating two or more variables to each other. eg multiplied

Question 27

Give examples of derived variables. 3

Answer 27

1. Rate
2. Ratios
3. Percentages

Question 28

Define accuracy of data.

Answer 28

The closeness of a measured or computed value to the true value,

i.e points on or near bull’s eye. well calibrated

Question 29

Define precision

Answer 29

The closeness of repeated measurements to each other i.e is the instrument precise?

Question 30

To keep in line with reproducibility of a procedure data obtained must be both accurate and precise. True or false ?

Answer 30

True

Question 31

The distribution of a continuous variable e.g. weight is of considerable biological interest. True or false

Answer 31

True. It can give information about the population and/or scale of measurement used.

Question 32

Name examples of frequency distribution graphs.

Answer 32

1. Symmetrical bell shaped curve
2. L shaped
3. J shaped
4. Right skewed - tail skewed on right side
5. Left skewed - tail skewed on left side