mercredi 22 mai 2013

Continuous and Discrete Data

What's a data?
  • Data is a collection of facts, such as values or measurements. 
  • It can be numbers, words, measurements, observations or even just descriptions of things. 
  • It can be qualitative or quantitative: the qualitative data describe information (it describes something)  and the quantitative data give numerical information (numbers).
Discrete Data 
  • Discrete data can only take particular values. Discrete data can be numeric,  like numbers of apples, but it can also be categorical like red or blue, or male or female, or good or bad.
  • Discrete data usually occurs in a case where there are only a certain number of values, or when we are counting something (using whole numbers).
  • For example: number of pages in book, shoes size, Number of people in race, they are all a discrete since they can only take an individual values.
Continuous Data 
  • Continuous data are not restricted to defined separate values, but can occupy any value over a continuous range. Between any two continuous data values there may be an infinite number of others. Continuous data are always essentially numeric.
  • For example: the height of trees at a nursery is an example of continuous data. Is it possible for a tree to be 76.2" tall? Sure. How about 76.29"? Yes. How about 76.2914563782"?  The possibilities depends upon the accuracy of our measuring device. 
To conclude...
One general way to tell if data is continuous is to ask yourself if it is possible for the data to take on values that are fractions or decimals. If your answer is yes, this is usually continuous data. 
What do we know about the Cat arrow ?
Qualitative Data:
-He is brown and black
-He has long hair
-He has lots of energy 

Quantitative Data:
-Discrete Data: He has 4 legs. He has 6 brothers. ect
-Continuous Data: He weighs 5.5 kg. He is 57 mm tall. ect