Introduction to Biostatistics Flashcards
Define statistics
The scientific study of numerical data based on natural phenomena.
With the definition of statistics, biostatics can then said to be?
The application of statistical methods to the solution of biological phenomena
What does biostatics help one identify?
Patterns of importance in nature and life.
To accepted as scientific evidence what criteria must statistics meet? (2)
- Be objective
- Adhere to general ethical code of scientific methodology
Give one example of a general ethic required in scientific methodology.
Reproducibility
What does the term natural phenomena mean?
It applies to all events that occur in biotic and abiotic factors outside control of human beings.
Do events evoked by scientists during experiments count as natural phenomena? Yes or No
Yes they do.
What is data?
collection of facts and figures/information that can be in any form—numerical or non-numerical
What data does statistics generally deal with?
variables obtained a collection of individual observations
In statistics, how are observations expressed?
Objectively quantified with degree of belief or disbelief expressed as a probability.
In statistics objects/phenomena under study can be classified as populations, samples and individual. Define what population is?
Collection of individuals under consideration in a statistical study.
Example 1000 tomatoes
What then is a sample?
A collection of individuals selected from a population by specified procedure.
Example, 100 tomatoes from population of 1000 tomatoes
What then is an individual?
The smallest sampling unit.
example, 1 tomato
The property measured from the individuals under consideration is the?
Variable.
E.g. Weight of tomatoes
In light of individuals under consideration, what is a variable in statistics?
A shared property which differs in some measurable way from individual to individual.
E.g. weight
What are the two types of variables?
- Quantitative
- Qualitative
What are qualitative variables and give two examples.
They are non-numerical values
E.g. name of a restaurant
blood type
List the types of numerical/quantitative variables. 4. Think of a table of variables of eg wildlife survey.
- Continuous - a measurement of sth
- Discrete/categorical/nominal - a count of sth
- Attributes
- Derived
How are continuous variables quantified?
They are measured i.e. ascertain the size, amount, or degree of (something) by using an instrument or device marked in standard units.
What is a defining characteristic of continuous variables? Think time, continuous
They are infinite/ have no end
Give three examples of continuous variables.
- Time
- Length
- Weight
How are discrete variables quantified?
They are counted
Discrete values are also known as?
Categorical or ordinal or nominal
Give an example of a discrete variable
Number of red cars or number of students
Attribute variables are ranked according to the attributes or characteristics of individual. True or false?
True
Define derived variables.
Variables based on relating two or more variables to each other. eg multiplied
Give examples of derived variables. 3
- Rate
- Ratios
- Percentages
Define accuracy of data.
The closeness of a measured or computed value to the true value,
i.e points on or near bull’s eye. well calibrated
Define precision
The closeness of repeated measurements to each other i.e is the instrument precise?
To keep in line with reproducibility of a procedure data obtained must be both accurate and precise. True or false ?
True
The distribution of a continuous variable e.g. weight is of considerable biological interest. True or false
True. It can give information about the population and/or scale of measurement used.
Name examples of frequency distribution graphs.
- Symmetrical bell shaped curve
- L shaped
- J shaped
- Right skewed - tail skewed on right side
- Left skewed - tail skewed on left side
